diff --git a/README.md b/README.md
index b0669d2..0acd910 100644
--- a/README.md
+++ b/README.md
@@ -1,16 +1,16 @@
 # Backbone-Rails [![Build Status](https://secure.travis-ci.org/codebrew/backbone-rails.png)](http://travis-ci.org/codebrew/backbone-rails)[![Gem Version](https://badge.fury.io/rb/rails-backbone.png)](http://badge.fury.io/rb/rails-backbone)
 
-Easily setup and use backbone.js (1.1.2) with Rails 3.1 and greater
+Easily setup and use backbone.js (1.2.0) with Rails 3.1 and greater
 
 ##Version##
 
 ###Github master branch###
 
-Gem version : 1.1.2
+Gem version : 1.2.0
 
-Backbone version : 1.1.2
+Backbone version : 1.2.0
 
-Underscore version : 1.8.2
+Underscore version : 1.8.3
 
 ###Rubygems###
 
diff --git a/backbone-rails.gemspec b/backbone-rails.gemspec
index 3412ac5..ecff620 100644
--- a/backbone-rails.gemspec
+++ b/backbone-rails.gemspec
@@ -1,8 +1,8 @@
 # Provide a simple gemspec so you can easily use your
 # project in your rails apps through git.
 Gem::Specification.new do |s|
-  s.name = "rails-backbone"
-  s.version = "1.1.2"
+  s.name = "backbone-rails"
+  s.version = "1.2.0"
   s.authors     = ["Ryan Fitzgerald", "Code Brew Studios", "Manu S Ajith"]
   s.email       = ["ryan@codebrewstudios.com", "neo@codingarena.in"]
   s.homepage    = "http://github.com/codebrew/backbone-rails"
diff --git a/vendor/assets/javascripts/backbone.js b/vendor/assets/javascripts/backbone.js
index 24a550a..dd6425e 100644
--- a/vendor/assets/javascripts/backbone.js
+++ b/vendor/assets/javascripts/backbone.js
@@ -1,11 +1,16 @@
-//     Backbone.js 1.1.2
+//     Backbone.js 1.2.0
 
-//     (c) 2010-2014 Jeremy Ashkenas, DocumentCloud and Investigative Reporters & Editors
+//     (c) 2010-2015 Jeremy Ashkenas, DocumentCloud and Investigative Reporters & Editors
 //     Backbone may be freely distributed under the MIT license.
 //     For all details and documentation:
 //     http://backbonejs.org
 
-(function(root, factory) {
+(function(factory) {
+
+  // Establish the root object, `window` (`self`) in the browser, or `global` on the server.
+  // We use `self` instead of `window` for `WebWorker` support.
+  var root = (typeof self == 'object' && self.self == self && self) ||
+            (typeof global == 'object' && global.global == global && global);
 
   // Set up Backbone appropriately for the environment. Start with AMD.
   if (typeof define === 'function' && define.amd) {
@@ -17,15 +22,16 @@
 
   // Next for Node.js or CommonJS. jQuery may not be needed as a module.
   } else if (typeof exports !== 'undefined') {
-    var _ = require('underscore');
-    factory(root, exports, _);
+    var _ = require('underscore'), $;
+    try { $ = require('jquery'); } catch(e) {}
+    factory(root, exports, _, $);
 
   // Finally, as a browser global.
   } else {
     root.Backbone = factory(root, {}, root._, (root.jQuery || root.Zepto || root.ender || root.$));
   }
 
-}(this, function(root, Backbone, _, $) {
+}(function(root, Backbone, _, $) {
 
   // Initial Setup
   // -------------
@@ -36,12 +42,10 @@
 
   // Create local references to array methods we'll want to use later.
   var array = [];
-  var push = array.push;
   var slice = array.slice;
-  var splice = array.splice;
 
   // Current version of the library. Keep in sync with `package.json`.
-  Backbone.VERSION = '1.1.2';
+  Backbone.VERSION = '1.2.0';
 
   // For Backbone's purposes, jQuery, Zepto, Ender, or My Library (kidding) owns
   // the `$` variable.
@@ -60,7 +64,7 @@
   Backbone.emulateHTTP = false;
 
   // Turn on `emulateJSON` to support legacy servers that can't deal with direct
-  // `application/json` requests ... will encode the body as
+  // `application/json` requests ... this will encode the body as
   // `application/x-www-form-urlencoded` instead and will send the model in a
   // form param named `model`.
   Backbone.emulateJSON = false;
@@ -78,123 +82,235 @@
   //     object.on('expand', function(){ alert('expanded'); });
   //     object.trigger('expand');
   //
-  var Events = Backbone.Events = {
-
-    // Bind an event to a `callback` function. Passing `"all"` will bind
-    // the callback to all events fired.
-    on: function(name, callback, context) {
-      if (!eventsApi(this, 'on', name, [callback, context]) || !callback) return this;
-      this._events || (this._events = {});
-      var events = this._events[name] || (this._events[name] = []);
-      events.push({callback: callback, context: context, ctx: context || this});
-      return this;
-    },
+  var Events = Backbone.Events = {};
 
-    // Bind an event to only be triggered a single time. After the first time
-    // the callback is invoked, it will be removed.
-    once: function(name, callback, context) {
-      if (!eventsApi(this, 'once', name, [callback, context]) || !callback) return this;
-      var self = this;
-      var once = _.once(function() {
-        self.off(name, once);
-        callback.apply(this, arguments);
-      });
-      once._callback = callback;
-      return this.on(name, once, context);
-    },
-
-    // Remove one or many callbacks. If `context` is null, removes all
-    // callbacks with that function. If `callback` is null, removes all
-    // callbacks for the event. If `name` is null, removes all bound
-    // callbacks for all events.
-    off: function(name, callback, context) {
-      var retain, ev, events, names, i, l, j, k;
-      if (!this._events || !eventsApi(this, 'off', name, [callback, context])) return this;
-      if (!name && !callback && !context) {
-        this._events = void 0;
-        return this;
+  // Regular expression used to split event strings.
+  var eventSplitter = /\s+/;
+
+  // Iterates over the standard `event, callback` (as well as the fancy multiple
+  // space-separated events `"change blur", callback` and jQuery-style event
+  // maps `{event: callback}`), reducing them by manipulating `memo`.
+  // Passes a normalized single event name and callback, as well as any
+  // optional `opts`.
+  var eventsApi = function(iteratee, memo, name, callback, opts) {
+    var i = 0, names;
+    if (name && typeof name === 'object') {
+      // Handle event maps.
+      for (names = _.keys(name); i < names.length ; i++) {
+        memo = iteratee(memo, names[i], name[names[i]], opts);
       }
-      names = name ? [name] : _.keys(this._events);
-      for (i = 0, l = names.length; i < l; i++) {
-        name = names[i];
-        if (events = this._events[name]) {
-          this._events[name] = retain = [];
-          if (callback || context) {
-            for (j = 0, k = events.length; j < k; j++) {
-              ev = events[j];
-              if ((callback && callback !== ev.callback && callback !== ev.callback._callback) ||
-                  (context && context !== ev.context)) {
-                retain.push(ev);
-              }
-            }
-          }
-          if (!retain.length) delete this._events[name];
-        }
+    } else if (name && eventSplitter.test(name)) {
+      // Handle space separated event names.
+      for (names = name.split(eventSplitter); i < names.length; i++) {
+        memo = iteratee(memo, names[i], callback, opts);
       }
+    } else {
+      memo = iteratee(memo, name, callback, opts);
+    }
+    return memo;
+  };
 
-      return this;
-    },
+  // Bind an event to a `callback` function. Passing `"all"` will bind
+  // the callback to all events fired.
+  Events.on = function(name, callback, context) {
+    return internalOn(this, name, callback, context);
+  };
 
-    // Trigger one or many events, firing all bound callbacks. Callbacks are
-    // passed the same arguments as `trigger` is, apart from the event name
-    // (unless you're listening on `"all"`, which will cause your callback to
-    // receive the true name of the event as the first argument).
-    trigger: function(name) {
-      if (!this._events) return this;
-      var args = slice.call(arguments, 1);
-      if (!eventsApi(this, 'trigger', name, args)) return this;
-      var events = this._events[name];
-      var allEvents = this._events.all;
-      if (events) triggerEvents(events, args);
-      if (allEvents) triggerEvents(allEvents, arguments);
-      return this;
-    },
+  // An internal use `on` function, used to guard the `listening` argument from
+  // the public API.
+  var internalOn = function(obj, name, callback, context, listening) {
+    obj._events = eventsApi(onApi, obj._events || {}, name, callback, {
+        context: context,
+        ctx: obj,
+        listening: listening
+    });
 
-    // Tell this object to stop listening to either specific events ... or
-    // to every object it's currently listening to.
-    stopListening: function(obj, name, callback) {
-      var listeningTo = this._listeningTo;
-      if (!listeningTo) return this;
-      var remove = !name && !callback;
-      if (!callback && typeof name === 'object') callback = this;
-      if (obj) (listeningTo = {})[obj._listenId] = obj;
-      for (var id in listeningTo) {
-        obj = listeningTo[id];
-        obj.off(name, callback, this);
-        if (remove || _.isEmpty(obj._events)) delete this._listeningTo[id];
-      }
-      return this;
+    if (listening) {
+      var listeners = obj._listeners || (obj._listeners = {});
+      listeners[listening.id] = listening;
     }
 
+    return obj;
   };
 
-  // Regular expression used to split event strings.
-  var eventSplitter = /\s+/;
+  // Inversion-of-control versions of `on`. Tell *this* object to listen to
+  // an event in another object... keeping track of what it's listening to.
+  Events.listenTo =  function(obj, name, callback) {
+    if (!obj) return this;
+    var id = obj._listenId || (obj._listenId = _.uniqueId('l'));
+    var listeningTo = this._listeningTo || (this._listeningTo = {});
+    var listening = listeningTo[id];
+
+    // This object is not listening to any other events on `obj` yet.
+    // Setup the necessary references to track the listening callbacks.
+    if (!listening) {
+      var thisId = this._listenId || (this._listenId = _.uniqueId('l'));
+      listening = listeningTo[id] = {obj: obj, objId: id, id: thisId, listeningTo: listeningTo, count: 0};
+    }
 
-  // Implement fancy features of the Events API such as multiple event
-  // names `"change blur"` and jQuery-style event maps `{change: action}`
-  // in terms of the existing API.
-  var eventsApi = function(obj, action, name, rest) {
-    if (!name) return true;
+    // Bind callbacks on obj, and keep track of them on listening.
+    internalOn(obj, name, callback, this, listening);
+    return this;
+  };
+
+  // The reducing API that adds a callback to the `events` object.
+  var onApi = function(events, name, callback, options) {
+    if (callback) {
+      var handlers = events[name] || (events[name] = []);
+      var context = options.context, ctx = options.ctx, listening = options.listening;
+      if (listening) listening.count++;
+
+      handlers.push({ callback: callback, context: context, ctx: context || ctx, listening: listening });
+    }
+    return events;
+  };
+
+  // Remove one or many callbacks. If `context` is null, removes all
+  // callbacks with that function. If `callback` is null, removes all
+  // callbacks for the event. If `name` is null, removes all bound
+  // callbacks for all events.
+  Events.off =  function(name, callback, context) {
+    if (!this._events) return this;
+    this._events = eventsApi(offApi, this._events, name, callback, {
+        context: context,
+        listeners: this._listeners
+    });
+    return this;
+  };
+
+  // Tell this object to stop listening to either specific events ... or
+  // to every object it's currently listening to.
+  Events.stopListening =  function(obj, name, callback) {
+    var listeningTo = this._listeningTo;
+    if (!listeningTo) return this;
+
+    var ids = obj ? [obj._listenId] : _.keys(listeningTo);
+
+    for (var i = 0; i < ids.length; i++) {
+      var listening = listeningTo[ids[i]];
 
-    // Handle event maps.
-    if (typeof name === 'object') {
-      for (var key in name) {
-        obj[action].apply(obj, [key, name[key]].concat(rest));
+      // If listening doesn't exist, this object is not currently
+      // listening to obj. Break out early.
+      if (!listening) break;
+
+      listening.obj.off(name, callback, this);
+    }
+    if (_.isEmpty(listeningTo)) this._listeningTo = void 0;
+
+    return this;
+  };
+
+  // The reducing API that removes a callback from the `events` object.
+  var offApi = function(events, name, callback, options) {
+    // No events to consider.
+    if (!events) return;
+
+    var i = 0, length, listening;
+    var context = options.context, listeners = options.listeners;
+
+    // Delete all events listeners and "drop" events.
+    if (!name && !callback && !context) {
+      var ids = _.keys(listeners);
+      for (; i < ids.length; i++) {
+        listening = listeners[ids[i]];
+        delete listeners[listening.id];
+        delete listening.listeningTo[listening.objId];
       }
-      return false;
+      return;
     }
 
-    // Handle space separated event names.
-    if (eventSplitter.test(name)) {
-      var names = name.split(eventSplitter);
-      for (var i = 0, l = names.length; i < l; i++) {
-        obj[action].apply(obj, [names[i]].concat(rest));
+    var names = name ? [name] : _.keys(events);
+    for (; i < names.length; i++) {
+      name = names[i];
+      var handlers = events[name];
+
+      // Bail out if there are no events stored.
+      if (!handlers) break;
+
+      // Replace events if there are any remaining.  Otherwise, clean up.
+      var remaining = [];
+      for (var j = 0; j < handlers.length; j++) {
+        var handler = handlers[j];
+        if (
+          callback && callback !== handler.callback &&
+            callback !== handler.callback._callback ||
+              context && context !== handler.context
+        ) {
+          remaining.push(handler);
+        } else {
+          listening = handler.listening;
+          if (listening && --listening.count === 0) {
+            delete listeners[listening.id];
+            delete listening.listeningTo[listening.objId];
+          }
+        }
+      }
+
+      // Update tail event if the list has any events.  Otherwise, clean up.
+      if (remaining.length) {
+        events[name] = remaining;
+      } else {
+        delete events[name];
       }
-      return false;
     }
+    if (_.size(events)) return events;
+  };
 
-    return true;
+  // Bind an event to only be triggered a single time. After the first time
+  // the callback is invoked, it will be removed. When multiple events are
+  // passed in using the space-separated syntax, the event will fire once for every
+  // event you passed in, not once for a combination of all events
+  Events.once =  function(name, callback, context) {
+    // Map the event into a `{event: once}` object.
+    var events = eventsApi(onceMap, {}, name, callback, _.bind(this.off, this));
+    return this.on(events, void 0, context);
+  };
+
+  // Inversion-of-control versions of `once`.
+  Events.listenToOnce =  function(obj, name, callback) {
+    // Map the event into a `{event: once}` object.
+    var events = eventsApi(onceMap, {}, name, callback, _.bind(this.stopListening, this, obj));
+    return this.listenTo(obj, events);
+  };
+
+  // Reduces the event callbacks into a map of `{event: onceWrapper}`.
+  // `offer` unbinds the `onceWrapper` after it as been called.
+  var onceMap = function(map, name, callback, offer) {
+    if (callback) {
+      var once = map[name] = _.once(function() {
+        offer(name, once);
+        callback.apply(this, arguments);
+      });
+      once._callback = callback;
+    }
+    return map;
+  };
+
+  // Trigger one or many events, firing all bound callbacks. Callbacks are
+  // passed the same arguments as `trigger` is, apart from the event name
+  // (unless you're listening on `"all"`, which will cause your callback to
+  // receive the true name of the event as the first argument).
+  Events.trigger =  function(name) {
+    if (!this._events) return this;
+
+    var length = Math.max(0, arguments.length - 1);
+    var args = Array(length);
+    for (var i = 0; i < length; i++) args[i] = arguments[i + 1];
+
+    eventsApi(triggerApi, this._events, name, void 0, args);
+    return this;
+  };
+
+  // Handles triggering the appropriate event callbacks.
+  var triggerApi = function(objEvents, name, cb, args) {
+    if (objEvents) {
+      var events = objEvents[name];
+      var allEvents = objEvents.all;
+      if (events && allEvents) allEvents = allEvents.slice();
+      if (events) triggerEvents(events, args);
+      if (allEvents) triggerEvents(allEvents, [name].concat(args));
+    }
+    return objEvents;
   };
 
   // A difficult-to-believe, but optimized internal dispatch function for
@@ -211,21 +327,34 @@
     }
   };
 
-  var listenMethods = {listenTo: 'on', listenToOnce: 'once'};
-
-  // Inversion-of-control versions of `on` and `once`. Tell *this* object to
-  // listen to an event in another object ... keeping track of what it's
-  // listening to.
-  _.each(listenMethods, function(implementation, method) {
-    Events[method] = function(obj, name, callback) {
-      var listeningTo = this._listeningTo || (this._listeningTo = {});
-      var id = obj._listenId || (obj._listenId = _.uniqueId('l'));
-      listeningTo[id] = obj;
-      if (!callback && typeof name === 'object') callback = this;
-      obj[implementation](name, callback, this);
-      return this;
-    };
-  });
+  // Proxy Underscore methods to a Backbone class' prototype using a
+  // particular attribute as the data argument
+  var addMethod = function(length, method, attribute) {
+    switch (length) {
+      case 1: return function() {
+        return _[method](this[attribute]);
+      };
+      case 2: return function(value) {
+        return _[method](this[attribute], value);
+      };
+      case 3: return function(iteratee, context) {
+        return _[method](this[attribute], iteratee, context);
+      };
+      case 4: return function(iteratee, defaultVal, context) {
+        return _[method](this[attribute], iteratee, defaultVal, context);
+      };
+      default: return function() {
+        var args = slice.call(arguments);
+        args.unshift(this[attribute]);
+        return _[method].apply(_, args);
+      };
+    }
+  };
+  var addUnderscoreMethods = function(Class, methods, attribute) {
+    _.each(methods, function(length, method) {
+      if (_[method]) Class.prototype[method] = addMethod(length, method, attribute);
+    });
+  };
 
   // Aliases for backwards compatibility.
   Events.bind   = Events.on;
@@ -248,7 +377,7 @@
   var Model = Backbone.Model = function(attributes, options) {
     var attrs = attributes || {};
     options || (options = {});
-    this.cid = _.uniqueId('c');
+    this.cid = _.uniqueId(this.cidPrefix);
     this.attributes = {};
     if (options.collection) this.collection = options.collection;
     if (options.parse) attrs = this.parse(attrs, options) || {};
@@ -271,6 +400,10 @@
     // CouchDB users may want to set this to `"_id"`.
     idAttribute: 'id',
 
+    // The prefix is used to create the client id which is used to identify models locally.
+    // You may want to override this if you're experiencing name clashes with model ids.
+    cidPrefix: 'c',
+
     // Initialize is an empty function by default. Override it with your own
     // initialization logic.
     initialize: function(){},
@@ -302,6 +435,11 @@
       return this.get(attr) != null;
     },
 
+    // Special-cased proxy to underscore's `_.matches` method.
+    matches: function(attrs) {
+      return !!_.iteratee(attrs, this)(this.attributes);
+    },
+
     // Set a hash of model attributes on the object, firing `"change"`. This is
     // the core primitive operation of a model, updating the data and notifying
     // anyone who needs to know about the change in state. The heart of the beast.
@@ -353,7 +491,7 @@
       // Trigger all relevant attribute changes.
       if (!silent) {
         if (changes.length) this._pending = options;
-        for (var i = 0, l = changes.length; i < l; i++) {
+        for (var i = 0; i < changes.length; i++) {
           this.trigger('change:' + changes[i], this, current[changes[i]], options);
         }
       }
@@ -423,9 +561,8 @@
       return _.clone(this._previousAttributes);
     },
 
-    // Fetch the model from the server. If the server's representation of the
-    // model differs from its current attributes, they will be overridden,
-    // triggering a `"change"` event.
+    // Fetch the model from the server, merging the response with the model's
+    // local attributes. Any changed attributes will trigger a "change" event.
     fetch: function(options) {
       options = options ? _.clone(options) : {};
       if (options.parse === void 0) options.parse = true;
@@ -433,7 +570,7 @@
       var success = options.success;
       options.success = function(resp) {
         if (!model.set(model.parse(resp, options), options)) return false;
-        if (success) success(model, resp, options);
+        if (success) success.call(options.context, model, resp, options);
         model.trigger('sync', model, resp, options);
       };
       wrapError(this, options);
@@ -444,7 +581,7 @@
     // If the server returns an attributes hash that differs, the model's
     // state will be `set` again.
     save: function(key, val, options) {
-      var attrs, method, xhr, attributes = this.attributes;
+      var attrs, method, xhr, attributes = this.attributes, wait;
 
       // Handle both `"key", value` and `{key: value}` -style arguments.
       if (key == null || typeof key === 'object') {
@@ -455,18 +592,19 @@
       }
 
       options = _.extend({validate: true}, options);
+      wait = options.wait;
 
       // If we're not waiting and attributes exist, save acts as
       // `set(attr).save(null, opts)` with validation. Otherwise, check if
       // the model will be valid when the attributes, if any, are set.
-      if (attrs && !options.wait) {
+      if (attrs && !wait) {
         if (!this.set(attrs, options)) return false;
       } else {
         if (!this._validate(attrs, options)) return false;
       }
 
       // Set temporary attributes if `{wait: true}`.
-      if (attrs && options.wait) {
+      if (attrs && wait) {
         this.attributes = _.extend({}, attributes, attrs);
       }
 
@@ -478,22 +616,22 @@
       options.success = function(resp) {
         // Ensure attributes are restored during synchronous saves.
         model.attributes = attributes;
-        var serverAttrs = model.parse(resp, options);
-        if (options.wait) serverAttrs = _.extend(attrs || {}, serverAttrs);
+        var serverAttrs = options.parse ? model.parse(resp, options) : resp;
+        if (wait) serverAttrs = _.extend(attrs || {}, serverAttrs);
         if (_.isObject(serverAttrs) && !model.set(serverAttrs, options)) {
           return false;
         }
-        if (success) success(model, resp, options);
+        if (success) success.call(options.context, model, resp, options);
         model.trigger('sync', model, resp, options);
       };
       wrapError(this, options);
 
       method = this.isNew() ? 'create' : (options.patch ? 'patch' : 'update');
-      if (method === 'patch') options.attrs = attrs;
+      if (method === 'patch' && !options.attrs) options.attrs = attrs;
       xhr = this.sync(method, this, options);
 
       // Restore attributes.
-      if (attrs && options.wait) this.attributes = attributes;
+      if (attrs && wait) this.attributes = attributes;
 
       return xhr;
     },
@@ -505,25 +643,27 @@
       options = options ? _.clone(options) : {};
       var model = this;
       var success = options.success;
+      var wait = options.wait;
 
       var destroy = function() {
+        model.stopListening();
         model.trigger('destroy', model, model.collection, options);
       };
 
       options.success = function(resp) {
-        if (options.wait || model.isNew()) destroy();
-        if (success) success(model, resp, options);
+        if (wait) destroy();
+        if (success) success.call(options.context, model, resp, options);
         if (!model.isNew()) model.trigger('sync', model, resp, options);
       };
 
+      var xhr = false;
       if (this.isNew()) {
-        options.success();
-        return false;
+        _.defer(options.success);
+      } else {
+        wrapError(this, options);
+        xhr = this.sync('delete', this, options);
       }
-      wrapError(this, options);
-
-      var xhr = this.sync('delete', this, options);
-      if (!options.wait) destroy();
+      if (!wait) destroy();
       return xhr;
     },
 
@@ -536,7 +676,8 @@
         _.result(this.collection, 'url') ||
         urlError();
       if (this.isNew()) return base;
-      return base.replace(/([^\/])$/, '$1/') + encodeURIComponent(this.id);
+      var id = this.id || this.attributes[this.idAttribute];
+      return base.replace(/([^\/])$/, '$1/') + encodeURIComponent(id);
     },
 
     // **parse** converts a response into the hash of attributes to be `set` on
@@ -574,22 +715,17 @@
   });
 
   // Underscore methods that we want to implement on the Model.
-  var modelMethods = ['keys', 'values', 'pairs', 'invert', 'pick', 'omit'];
+  var modelMethods = { keys: 1, values: 1, pairs: 1, invert: 1, pick: 0,
+      omit: 0, chain: 1, isEmpty: 1 };
 
   // Mix in each Underscore method as a proxy to `Model#attributes`.
-  _.each(modelMethods, function(method) {
-    Model.prototype[method] = function() {
-      var args = slice.call(arguments);
-      args.unshift(this.attributes);
-      return _[method].apply(_, args);
-    };
-  });
+  addUnderscoreMethods(Model, modelMethods, 'attributes');
 
   // Backbone.Collection
   // -------------------
 
   // If models tend to represent a single row of data, a Backbone Collection is
-  // more analagous to a table full of data ... or a small slice or page of that
+  // more analogous to a table full of data ... or a small slice or page of that
   // table, or a collection of rows that belong together for a particular reason
   // -- all of the messages in this particular folder, all of the documents
   // belonging to this particular author, and so on. Collections maintain
@@ -640,24 +776,11 @@
 
     // Remove a model, or a list of models from the set.
     remove: function(models, options) {
-      var singular = !_.isArray(models);
+      var singular = !_.isArray(models), removed;
       models = singular ? [models] : _.clone(models);
       options || (options = {});
-      var i, l, index, model;
-      for (i = 0, l = models.length; i < l; i++) {
-        model = models[i] = this.get(models[i]);
-        if (!model) continue;
-        delete this._byId[model.id];
-        delete this._byId[model.cid];
-        index = this.indexOf(model);
-        this.models.splice(index, 1);
-        this.length--;
-        if (!options.silent) {
-          options.index = index;
-          model.trigger('remove', model, this, options);
-        }
-        this._removeReference(model, options);
-      }
+      removed = this._removeModels(models, options);
+      if (!options.silent && removed) this.trigger('update', this, options);
       return singular ? models[0] : models;
     },
 
@@ -669,32 +792,29 @@
       options = _.defaults({}, options, setOptions);
       if (options.parse) models = this.parse(models, options);
       var singular = !_.isArray(models);
-      models = singular ? (models ? [models] : []) : _.clone(models);
-      var i, l, id, model, attrs, existing, sort;
+      models = singular ? (models ? [models] : []) : models.slice();
+      var id, model, attrs, existing, sort;
       var at = options.at;
-      var targetModel = this.model;
+      if (at != null) at = +at;
+      if (at < 0) at += this.length + 1;
       var sortable = this.comparator && (at == null) && options.sort !== false;
       var sortAttr = _.isString(this.comparator) ? this.comparator : null;
       var toAdd = [], toRemove = [], modelMap = {};
       var add = options.add, merge = options.merge, remove = options.remove;
       var order = !sortable && add && remove ? [] : false;
+      var orderChanged = false;
 
       // Turn bare objects into model references, and prevent invalid models
       // from being added.
-      for (i = 0, l = models.length; i < l; i++) {
-        attrs = models[i] || {};
-        if (attrs instanceof Model) {
-          id = model = attrs;
-        } else {
-          id = attrs[targetModel.prototype.idAttribute || 'id'];
-        }
+      for (var i = 0; i < models.length; i++) {
+        attrs = models[i];
 
         // If a duplicate is found, prevent it from being added and
         // optionally merge it into the existing model.
-        if (existing = this.get(id)) {
+        if (existing = this.get(attrs)) {
           if (remove) modelMap[existing.cid] = true;
-          if (merge) {
-            attrs = attrs === model ? model.attributes : attrs;
+          if (merge && attrs !== existing) {
+            attrs = this._isModel(attrs) ? attrs.attributes : attrs;
             if (options.parse) attrs = existing.parse(attrs, options);
             existing.set(attrs, options);
             if (sortable && !sort && existing.hasChanged(sortAttr)) sort = true;
@@ -711,30 +831,38 @@
 
         // Do not add multiple models with the same `id`.
         model = existing || model;
-        if (order && (model.isNew() || !modelMap[model.id])) order.push(model);
-        modelMap[model.id] = true;
+        if (!model) continue;
+        id = this.modelId(model.attributes);
+        if (order && (model.isNew() || !modelMap[id])) {
+          order.push(model);
+
+          // Check to see if this is actually a new model at this index.
+          orderChanged = orderChanged || !this.models[i] || model.cid !== this.models[i].cid;
+        }
+
+        modelMap[id] = true;
       }
 
       // Remove nonexistent models if appropriate.
       if (remove) {
-        for (i = 0, l = this.length; i < l; ++i) {
+        for (var i = 0; i < this.length; i++) {
           if (!modelMap[(model = this.models[i]).cid]) toRemove.push(model);
         }
-        if (toRemove.length) this.remove(toRemove, options);
+        if (toRemove.length) this._removeModels(toRemove, options);
       }
 
       // See if sorting is needed, update `length` and splice in new models.
-      if (toAdd.length || (order && order.length)) {
+      if (toAdd.length || orderChanged) {
         if (sortable) sort = true;
         this.length += toAdd.length;
         if (at != null) {
-          for (i = 0, l = toAdd.length; i < l; i++) {
+          for (var i = 0; i < toAdd.length; i++) {
             this.models.splice(at + i, 0, toAdd[i]);
           }
         } else {
           if (order) this.models.length = 0;
           var orderedModels = order || toAdd;
-          for (i = 0, l = orderedModels.length; i < l; i++) {
+          for (var i = 0; i < orderedModels.length; i++) {
             this.models.push(orderedModels[i]);
           }
         }
@@ -745,10 +873,13 @@
 
       // Unless silenced, it's time to fire all appropriate add/sort events.
       if (!options.silent) {
-        for (i = 0, l = toAdd.length; i < l; i++) {
-          (model = toAdd[i]).trigger('add', model, this, options);
+        var addOpts = at != null ? _.clone(options) : options;
+        for (var i = 0; i < toAdd.length; i++) {
+          if (at != null) addOpts.index = at + i;
+          (model = toAdd[i]).trigger('add', model, this, addOpts);
         }
-        if (sort || (order && order.length)) this.trigger('sort', this, options);
+        if (sort || orderChanged) this.trigger('sort', this, options);
+        if (toAdd.length || toRemove.length) this.trigger('update', this, options);
       }
 
       // Return the added (or merged) model (or models).
@@ -760,8 +891,8 @@
     // any granular `add` or `remove` events. Fires `reset` when finished.
     // Useful for bulk operations and optimizations.
     reset: function(models, options) {
-      options || (options = {});
-      for (var i = 0, l = this.models.length; i < l; i++) {
+      options = options ? _.clone(options) : {};
+      for (var i = 0; i < this.models.length; i++) {
         this._removeReference(this.models[i], options);
       }
       options.previousModels = this.models;
@@ -803,23 +934,22 @@
     // Get a model from the set by id.
     get: function(obj) {
       if (obj == null) return void 0;
-      return this._byId[obj] || this._byId[obj.id] || this._byId[obj.cid];
+      var id = this.modelId(this._isModel(obj) ? obj.attributes : obj);
+      return this._byId[obj] || this._byId[id] || this._byId[obj.cid];
     },
 
     // Get the model at the given index.
     at: function(index) {
+      if (index < 0) index += this.length;
       return this.models[index];
     },
 
     // Return models with matching attributes. Useful for simple cases of
     // `filter`.
     where: function(attrs, first) {
-      if (_.isEmpty(attrs)) return first ? void 0 : [];
+      var matches = _.matches(attrs);
       return this[first ? 'find' : 'filter'](function(model) {
-        for (var key in attrs) {
-          if (attrs[key] !== model.get(key)) return false;
-        }
-        return true;
+        return matches(model.attributes);
       });
     },
 
@@ -863,7 +993,7 @@
       options.success = function(resp) {
         var method = options.reset ? 'reset' : 'set';
         collection[method](resp, options);
-        if (success) success(collection, resp, options);
+        if (success) success.call(options.context, collection, resp, options);
         collection.trigger('sync', collection, resp, options);
       };
       wrapError(this, options);
@@ -875,13 +1005,14 @@
     // wait for the server to agree.
     create: function(model, options) {
       options = options ? _.clone(options) : {};
+      var wait = options.wait;
       if (!(model = this._prepareModel(model, options))) return false;
-      if (!options.wait) this.add(model, options);
+      if (!wait) this.add(model, options);
       var collection = this;
       var success = options.success;
-      options.success = function(model, resp) {
-        if (options.wait) collection.add(model, options);
-        if (success) success(model, resp, options);
+      options.success = function(model, resp, callbackOpts) {
+        if (wait) collection.add(model, callbackOpts);
+        if (success) success.call(callbackOpts.context, model, resp, callbackOpts);
       };
       model.save(null, options);
       return model;
@@ -895,7 +1026,15 @@
 
     // Create a new collection with an identical list of models as this one.
     clone: function() {
-      return new this.constructor(this.models);
+      return new this.constructor(this.models, {
+        model: this.model,
+        comparator: this.comparator
+      });
+    },
+
+    // Define how to uniquely identify models in the collection.
+    modelId: function (attrs) {
+      return attrs[this.model.prototype.idAttribute || 'id'];
     },
 
     // Private method to reset all internal state. Called when the collection
@@ -909,7 +1048,10 @@
     // Prepare a hash of attributes (or other model) to be added to this
     // collection.
     _prepareModel: function(attrs, options) {
-      if (attrs instanceof Model) return attrs;
+      if (this._isModel(attrs)) {
+        if (!attrs.collection) attrs.collection = this;
+        return attrs;
+      }
       options = options ? _.clone(options) : {};
       options.collection = this;
       var model = new this.model(attrs, options);
@@ -918,11 +1060,44 @@
       return false;
     },
 
+    // Internal method called by both remove and set. Does not trigger any
+    // additional events. Returns true if anything was actually removed.
+    _removeModels: function(models, options) {
+      var i, l, index, model, removed = false;
+      for (var i = 0, j = 0; i < models.length; i++) {
+        var model = models[i] = this.get(models[i]);
+        if (!model) continue;
+        var id = this.modelId(model.attributes);
+        if (id != null) delete this._byId[id];
+        delete this._byId[model.cid];
+        var index = this.indexOf(model);
+        this.models.splice(index, 1);
+        this.length--;
+        if (!options.silent) {
+          options.index = index;
+          model.trigger('remove', model, this, options);
+        }
+        models[j++] = model;
+        this._removeReference(model, options);
+        removed = true;
+      }
+      // We only need to slice if models array should be smaller, which is
+      // caused by some models not actually getting removed.
+      if (models.length !== j) models = models.slice(0, j);
+      return removed;
+    },
+
+    // Method for checking whether an object should be considered a model for
+    // the purposes of adding to the collection.
+    _isModel: function (model) {
+      return model instanceof Model;
+    },
+
     // Internal method to create a model's ties to a collection.
     _addReference: function(model, options) {
       this._byId[model.cid] = model;
-      if (model.id != null) this._byId[model.id] = model;
-      if (!model.collection) model.collection = this;
+      var id = this.modelId(model.attributes);
+      if (id != null) this._byId[id] = model;
       model.on('all', this._onModelEvent, this);
     },
 
@@ -939,9 +1114,13 @@
     _onModelEvent: function(event, model, collection, options) {
       if ((event === 'add' || event === 'remove') && collection !== this) return;
       if (event === 'destroy') this.remove(model, options);
-      if (model && event === 'change:' + model.idAttribute) {
-        delete this._byId[model.previous(model.idAttribute)];
-        if (model.id != null) this._byId[model.id] = model;
+      if (event === 'change') {
+        var prevId = this.modelId(model.previousAttributes());
+        var id = this.modelId(model.attributes);
+        if (prevId !== id) {
+          if (prevId != null) delete this._byId[prevId];
+          if (id != null) this._byId[id] = model;
+        }
       }
       this.trigger.apply(this, arguments);
     }
@@ -951,27 +1130,23 @@
   // Underscore methods that we want to implement on the Collection.
   // 90% of the core usefulness of Backbone Collections is actually implemented
   // right here:
-  var methods = ['forEach', 'each', 'map', 'collect', 'reduce', 'foldl',
-    'inject', 'reduceRight', 'foldr', 'find', 'detect', 'filter', 'select',
-    'reject', 'every', 'all', 'some', 'any', 'include', 'contains', 'invoke',
-    'max', 'min', 'toArray', 'size', 'first', 'head', 'take', 'initial', 'rest',
-    'tail', 'drop', 'last', 'without', 'difference', 'indexOf', 'shuffle',
-    'lastIndexOf', 'isEmpty', 'chain', 'sample'];
+  var collectionMethods = { forEach: 3, each: 3, map: 3, collect: 3, reduce: 4,
+      foldl: 4, inject: 4, reduceRight: 4, foldr: 4, find: 3, detect: 3, filter: 3,
+      select: 3, reject: 3, every: 3, all: 3, some: 3, any: 3, include: 2,
+      contains: 2, invoke: 2, max: 3, min: 3, toArray: 1, size: 1, first: 3,
+      head: 3, take: 3, initial: 3, rest: 3, tail: 3, drop: 3, last: 3,
+      without: 0, difference: 0, indexOf: 3, shuffle: 1, lastIndexOf: 3,
+      isEmpty: 1, chain: 1, sample: 3, partition: 3 };
 
   // Mix in each Underscore method as a proxy to `Collection#models`.
-  _.each(methods, function(method) {
-    Collection.prototype[method] = function() {
-      var args = slice.call(arguments);
-      args.unshift(this.models);
-      return _[method].apply(_, args);
-    };
-  });
+  addUnderscoreMethods(Collection, collectionMethods, 'models');
 
   // Underscore methods that take a property name as an argument.
   var attributeMethods = ['groupBy', 'countBy', 'sortBy', 'indexBy'];
 
   // Use attributes instead of properties.
   _.each(attributeMethods, function(method) {
+    if (!_[method]) return;
     Collection.prototype[method] = function(value, context) {
       var iterator = _.isFunction(value) ? value : function(model) {
         return model.get(value);
@@ -999,7 +1174,6 @@
     _.extend(this, _.pick(options, viewOptions));
     this._ensureElement();
     this.initialize.apply(this, arguments);
-    this.delegateEvents();
   };
 
   // Cached regex to split keys for `delegate`.
@@ -1034,21 +1208,37 @@
     // Remove this view by taking the element out of the DOM, and removing any
     // applicable Backbone.Events listeners.
     remove: function() {
-      this.$el.remove();
+      this._removeElement();
       this.stopListening();
       return this;
     },
 
-    // Change the view's element (`this.el` property), including event
-    // re-delegation.
-    setElement: function(element, delegate) {
-      if (this.$el) this.undelegateEvents();
-      this.$el = element instanceof Backbone.$ ? element : Backbone.$(element);
-      this.el = this.$el[0];
-      if (delegate !== false) this.delegateEvents();
+    // Remove this view's element from the document and all event listeners
+    // attached to it. Exposed for subclasses using an alternative DOM
+    // manipulation API.
+    _removeElement: function() {
+      this.$el.remove();
+    },
+
+    // Change the view's element (`this.el` property) and re-delegate the
+    // view's events on the new element.
+    setElement: function(element) {
+      this.undelegateEvents();
+      this._setElement(element);
+      this.delegateEvents();
       return this;
     },
 
+    // Creates the `this.el` and `this.$el` references for this view using the
+    // given `el`. `el` can be a CSS selector or an HTML string, a jQuery
+    // context or an element. Subclasses can override this to utilize an
+    // alternative DOM manipulation API and are only required to set the
+    // `this.el` property.
+    _setElement: function(el) {
+      this.$el = el instanceof Backbone.$ ? el : Backbone.$(el);
+      this.el = this.$el[0];
+    },
+
     // Set callbacks, where `this.events` is a hash of
     //
     // *{"event selector": "callback"}*
@@ -1062,8 +1252,6 @@
     // pairs. Callbacks will be bound to the view, with `this` set properly.
     // Uses event delegation for efficiency.
     // Omitting the selector binds the event to `this.el`.
-    // This only works for delegate-able events: not `focus`, `blur`, and
-    // not `change`, `submit`, and `reset` in Internet Explorer.
     delegateEvents: function(events) {
       if (!(events || (events = _.result(this, 'events')))) return this;
       this.undelegateEvents();
@@ -1071,28 +1259,39 @@
         var method = events[key];
         if (!_.isFunction(method)) method = this[events[key]];
         if (!method) continue;
-
         var match = key.match(delegateEventSplitter);
-        var eventName = match[1], selector = match[2];
-        method = _.bind(method, this);
-        eventName += '.delegateEvents' + this.cid;
-        if (selector === '') {
-          this.$el.on(eventName, method);
-        } else {
-          this.$el.on(eventName, selector, method);
-        }
+        this.delegate(match[1], match[2], _.bind(method, this));
       }
       return this;
     },
 
-    // Clears all callbacks previously bound to the view with `delegateEvents`.
+    // Add a single event listener to the view's element (or a child element
+    // using `selector`). This only works for delegate-able events: not `focus`,
+    // `blur`, and not `change`, `submit`, and `reset` in Internet Explorer.
+    delegate: function(eventName, selector, listener) {
+      this.$el.on(eventName + '.delegateEvents' + this.cid, selector, listener);
+    },
+
+    // Clears all callbacks previously bound to the view by `delegateEvents`.
     // You usually don't need to use this, but may wish to if you have multiple
     // Backbone views attached to the same DOM element.
     undelegateEvents: function() {
-      this.$el.off('.delegateEvents' + this.cid);
+      if (this.$el) this.$el.off('.delegateEvents' + this.cid);
       return this;
     },
 
+    // A finer-grained `undelegateEvents` for removing a single delegated event.
+    // `selector` and `listener` are both optional.
+    undelegate: function(eventName, selector, listener) {
+      this.$el.off(eventName + '.delegateEvents' + this.cid, selector, listener);
+    },
+
+    // Produces a DOM element to be assigned to your view. Exposed for
+    // subclasses using an alternative DOM manipulation API.
+    _createElement: function(tagName) {
+      return document.createElement(tagName);
+    },
+
     // Ensure that the View has a DOM element to render into.
     // If `this.el` is a string, pass it through `$()`, take the first
     // matching element, and re-assign it to `el`. Otherwise, create
@@ -1102,11 +1301,17 @@
         var attrs = _.extend({}, _.result(this, 'attributes'));
         if (this.id) attrs.id = _.result(this, 'id');
         if (this.className) attrs['class'] = _.result(this, 'className');
-        var $el = Backbone.$('<' + _.result(this, 'tagName') + '>').attr(attrs);
-        this.setElement($el, false);
+        this.setElement(this._createElement(_.result(this, 'tagName')));
+        this._setAttributes(attrs);
       } else {
-        this.setElement(_.result(this, 'el'), false);
+        this.setElement(_.result(this, 'el'));
       }
+    },
+
+    // Set attributes from a hash on this view's element.  Exposed for
+    // subclasses using an alternative DOM manipulation API.
+    _setAttributes: function(attributes) {
+      this.$el.attr(attributes);
     }
 
   });
@@ -1175,14 +1380,13 @@
       params.processData = false;
     }
 
-    // If we're sending a `PATCH` request, and we're in an old Internet Explorer
-    // that still has ActiveX enabled by default, override jQuery to use that
-    // for XHR instead. Remove this line when jQuery supports `PATCH` on IE8.
-    if (params.type === 'PATCH' && noXhrPatch) {
-      params.xhr = function() {
-        return new ActiveXObject("Microsoft.XMLHTTP");
-      };
-    }
+    // Pass along `textStatus` and `errorThrown` from jQuery.
+    var error = options.error;
+    options.error = function(xhr, textStatus, errorThrown) {
+      options.textStatus = textStatus;
+      options.errorThrown = errorThrown;
+      if (error) error.call(options.context, xhr, textStatus, errorThrown);
+    };
 
     // Make the request, allowing the user to override any Ajax options.
     var xhr = options.xhr = Backbone.ajax(_.extend(params, options));
@@ -1190,10 +1394,6 @@
     return xhr;
   };
 
-  var noXhrPatch =
-    typeof window !== 'undefined' && !!window.ActiveXObject &&
-      !(window.XMLHttpRequest && (new XMLHttpRequest).dispatchEvent);
-
   // Map from CRUD to HTTP for our default `Backbone.sync` implementation.
   var methodMap = {
     'create': 'POST',
@@ -1251,17 +1451,18 @@
       var router = this;
       Backbone.history.route(route, function(fragment) {
         var args = router._extractParameters(route, fragment);
-        router.execute(callback, args);
-        router.trigger.apply(router, ['route:' + name].concat(args));
-        router.trigger('route', name, args);
-        Backbone.history.trigger('route', router, name, args);
+        if (router.execute(callback, args, name) !== false) {
+          router.trigger.apply(router, ['route:' + name].concat(args));
+          router.trigger('route', name, args);
+          Backbone.history.trigger('route', router, name, args);
+        }
       });
       return this;
     },
 
     // Execute a route handler with the provided parameters.  This is an
     // excellent place to do pre-route setup or post-route cleanup.
-    execute: function(callback, args) {
+    execute: function(callback, args, name) {
       if (callback) callback.apply(this, args);
     },
 
@@ -1334,12 +1535,6 @@
   // Cached regex for stripping leading and trailing slashes.
   var rootStripper = /^\/+|\/+$/g;
 
-  // Cached regex for detecting MSIE.
-  var isExplorer = /msie [\w.]+/;
-
-  // Cached regex for removing a trailing slash.
-  var trailingSlash = /\/$/;
-
   // Cached regex for stripping urls of hash.
   var pathStripper = /#.*$/;
 
@@ -1355,7 +1550,29 @@
 
     // Are we at the app root?
     atRoot: function() {
-      return this.location.pathname.replace(/[^\/]$/, '$&/') === this.root;
+      var path = this.location.pathname.replace(/[^\/]$/, '$&/');
+      return path === this.root && !this.getSearch();
+    },
+
+    // Does the pathname match the root?
+    matchRoot: function() {
+      var path = this.decodeFragment(this.location.pathname);
+      var root = path.slice(0, this.root.length - 1) + '/';
+      return root === this.root;
+    },
+
+    // Unicode characters in `location.pathname` are percent encoded so they're
+    // decoded for comparison. `%25` should not be decoded since it may be part
+    // of an encoded parameter.
+    decodeFragment: function(fragment) {
+      return decodeURI(fragment.replace(/%25/g, '%2525'));
+    },
+
+    // In IE6, the hash fragment and search params are incorrect if the
+    // fragment contains `?`.
+    getSearch: function() {
+      var match = this.location.href.replace(/#.*/, '').match(/\?.+/);
+      return match ? match[0] : '';
     },
 
     // Gets the true hash value. Cannot use location.hash directly due to bug
@@ -1365,14 +1582,19 @@
       return match ? match[1] : '';
     },
 
-    // Get the cross-browser normalized URL fragment, either from the URL,
-    // the hash, or the override.
-    getFragment: function(fragment, forcePushState) {
+    // Get the pathname and search params, without the root.
+    getPath: function() {
+      var path = this.decodeFragment(
+        this.location.pathname + this.getSearch()
+      ).slice(this.root.length - 1);
+      return path.charAt(0) === '/' ? path.slice(1) : path;
+    },
+
+    // Get the cross-browser normalized URL fragment from the path or hash.
+    getFragment: function(fragment) {
       if (fragment == null) {
-        if (this._hasPushState || !this._wantsHashChange || forcePushState) {
-          fragment = decodeURI(this.location.pathname + this.location.search);
-          var root = this.root.replace(trailingSlash, '');
-          if (!fragment.indexOf(root)) fragment = fragment.slice(root.length);
+        if (this._usePushState || !this._wantsHashChange) {
+          fragment = this.getPath();
         } else {
           fragment = this.getHash();
         }
@@ -1383,7 +1605,7 @@
     // Start the hash change handling, returning `true` if the current URL matches
     // an existing route, and `false` otherwise.
     start: function(options) {
-      if (History.started) throw new Error("Backbone.history has already been started");
+      if (History.started) throw new Error('Backbone.history has already been started');
       History.started = true;
 
       // Figure out the initial configuration. Do we need an iframe?
@@ -1391,36 +1613,16 @@
       this.options          = _.extend({root: '/'}, this.options, options);
       this.root             = this.options.root;
       this._wantsHashChange = this.options.hashChange !== false;
+      this._hasHashChange   = 'onhashchange' in window;
+      this._useHashChange   = this._wantsHashChange && this._hasHashChange;
       this._wantsPushState  = !!this.options.pushState;
-      this._hasPushState    = !!(this.options.pushState && this.history && this.history.pushState);
-      var fragment          = this.getFragment();
-      var docMode           = document.documentMode;
-      var oldIE             = (isExplorer.exec(navigator.userAgent.toLowerCase()) && (!docMode || docMode <= 7));
+      this._hasPushState    = !!(this.history && this.history.pushState);
+      this._usePushState    = this._wantsPushState && this._hasPushState;
+      this.fragment         = this.getFragment();
 
       // Normalize root to always include a leading and trailing slash.
       this.root = ('/' + this.root + '/').replace(rootStripper, '/');
 
-      if (oldIE && this._wantsHashChange) {
-        var frame = Backbone.$('<iframe src="javascript:0" tabindex="-1">');
-        this.iframe = frame.hide().appendTo('body')[0].contentWindow;
-        this.navigate(fragment);
-      }
-
-      // Depending on whether we're using pushState or hashes, and whether
-      // 'onhashchange' is supported, determine how we check the URL state.
-      if (this._hasPushState) {
-        Backbone.$(window).on('popstate', this.checkUrl);
-      } else if (this._wantsHashChange && ('onhashchange' in window) && !oldIE) {
-        Backbone.$(window).on('hashchange', this.checkUrl);
-      } else if (this._wantsHashChange) {
-        this._checkUrlInterval = setInterval(this.checkUrl, this.interval);
-      }
-
-      // Determine if we need to change the base url, for a pushState link
-      // opened by a non-pushState browser.
-      this.fragment = fragment;
-      var loc = this.location;
-
       // Transition from hashChange to pushState or vice versa if both are
       // requested.
       if (this._wantsHashChange && this._wantsPushState) {
@@ -1428,27 +1630,74 @@
         // If we've started off with a route from a `pushState`-enabled
         // browser, but we're currently in a browser that doesn't support it...
         if (!this._hasPushState && !this.atRoot()) {
-          this.fragment = this.getFragment(null, true);
-          this.location.replace(this.root + '#' + this.fragment);
+          var root = this.root.slice(0, -1) || '/';
+          this.location.replace(root + '#' + this.getPath());
           // Return immediately as browser will do redirect to new url
           return true;
 
         // Or if we've started out with a hash-based route, but we're currently
         // in a browser where it could be `pushState`-based instead...
-        } else if (this._hasPushState && this.atRoot() && loc.hash) {
-          this.fragment = this.getHash().replace(routeStripper, '');
-          this.history.replaceState({}, document.title, this.root + this.fragment);
+        } else if (this._hasPushState && this.atRoot()) {
+          this.navigate(this.getHash(), {replace: true});
         }
 
       }
 
+      // Proxy an iframe to handle location events if the browser doesn't
+      // support the `hashchange` event, HTML5 history, or the user wants
+      // `hashChange` but not `pushState`.
+      if (!this._hasHashChange && this._wantsHashChange && !this._usePushState) {
+        var iframe = document.createElement('iframe');
+        iframe.src = 'javascript:0';
+        iframe.style.display = 'none';
+        iframe.tabIndex = -1;
+        var body = document.body;
+        // Using `appendChild` will throw on IE < 9 if the document is not ready.
+        this.iframe = body.insertBefore(iframe, body.firstChild).contentWindow;
+        this.iframe.document.open().close();
+        this.iframe.location.hash = '#' + this.fragment;
+      }
+
+      // Add a cross-platform `addEventListener` shim for older browsers.
+      var addEventListener = window.addEventListener || function (eventName, listener) {
+        return attachEvent('on' + eventName, listener);
+      };
+
+      // Depending on whether we're using pushState or hashes, and whether
+      // 'onhashchange' is supported, determine how we check the URL state.
+      if (this._usePushState) {
+        addEventListener('popstate', this.checkUrl, false);
+      } else if (this._useHashChange && !this.iframe) {
+        addEventListener('hashchange', this.checkUrl, false);
+      } else if (this._wantsHashChange) {
+        this._checkUrlInterval = setInterval(this.checkUrl, this.interval);
+      }
+
       if (!this.options.silent) return this.loadUrl();
     },
 
     // Disable Backbone.history, perhaps temporarily. Not useful in a real app,
     // but possibly useful for unit testing Routers.
     stop: function() {
-      Backbone.$(window).off('popstate', this.checkUrl).off('hashchange', this.checkUrl);
+      // Add a cross-platform `removeEventListener` shim for older browsers.
+      var removeEventListener = window.removeEventListener || function (eventName, listener) {
+        return detachEvent('on' + eventName, listener);
+      };
+
+      // Remove window listeners.
+      if (this._usePushState) {
+        removeEventListener('popstate', this.checkUrl, false);
+      } else if (this._useHashChange && !this.iframe) {
+        removeEventListener('hashchange', this.checkUrl, false);
+      }
+
+      // Clean up the iframe if necessary.
+      if (this.iframe) {
+        document.body.removeChild(this.iframe.frameElement);
+        this.iframe = null;
+      }
+
+      // Some environments will throw when clearing an undefined interval.
       if (this._checkUrlInterval) clearInterval(this._checkUrlInterval);
       History.started = false;
     },
@@ -1463,9 +1712,13 @@
     // calls `loadUrl`, normalizing across the hidden iframe.
     checkUrl: function(e) {
       var current = this.getFragment();
+
+      // If the user pressed the back button, the iframe's hash will have
+      // changed and we should use that for comparison.
       if (current === this.fragment && this.iframe) {
-        current = this.getFragment(this.getHash(this.iframe));
+        current = this.getHash(this.iframe);
       }
+
       if (current === this.fragment) return false;
       if (this.iframe) this.navigate(current);
       this.loadUrl();
@@ -1475,6 +1728,8 @@
     // match, returns `true`. If no defined routes matches the fragment,
     // returns `false`.
     loadUrl: function(fragment) {
+      // If the root doesn't match, no routes can match either.
+      if (!this.matchRoot()) return false;
       fragment = this.fragment = this.getFragment(fragment);
       return _.any(this.handlers, function(handler) {
         if (handler.route.test(fragment)) {
@@ -1495,30 +1750,35 @@
       if (!History.started) return false;
       if (!options || options === true) options = {trigger: !!options};
 
-      var url = this.root + (fragment = this.getFragment(fragment || ''));
+      // Normalize the fragment.
+      fragment = this.getFragment(fragment || '');
+
+      // Don't include a trailing slash on the root.
+      var root = this.root;
+      if (fragment === '' || fragment.charAt(0) === '?') {
+        root = root.slice(0, -1) || '/';
+      }
+      var url = root + fragment;
 
-      // Strip the hash for matching.
-      fragment = fragment.replace(pathStripper, '');
+      // Strip the hash and decode for matching.
+      fragment = this.decodeFragment(fragment.replace(pathStripper, ''));
 
       if (this.fragment === fragment) return;
       this.fragment = fragment;
 
-      // Don't include a trailing slash on the root.
-      if (fragment === '' && url !== '/') url = url.slice(0, -1);
-
       // If pushState is available, we use it to set the fragment as a real URL.
-      if (this._hasPushState) {
+      if (this._usePushState) {
         this.history[options.replace ? 'replaceState' : 'pushState']({}, document.title, url);
 
       // If hash changes haven't been explicitly disabled, update the hash
       // fragment to store history.
       } else if (this._wantsHashChange) {
         this._updateHash(this.location, fragment, options.replace);
-        if (this.iframe && (fragment !== this.getFragment(this.getHash(this.iframe)))) {
+        if (this.iframe && (fragment !== this.getHash(this.iframe))) {
           // Opening and closing the iframe tricks IE7 and earlier to push a
           // history entry on hash-tag change.  When replace is true, we don't
           // want this.
-          if(!options.replace) this.iframe.document.open().close();
+          if (!options.replace) this.iframe.document.open().close();
           this._updateHash(this.iframe.location, fragment, options.replace);
         }
 
@@ -1550,7 +1810,7 @@
   // Helpers
   // -------
 
-  // Helper function to correctly set up the prototype chain, for subclasses.
+  // Helper function to correctly set up the prototype chain for subclasses.
   // Similar to `goog.inherits`, but uses a hash of prototype properties and
   // class properties to be extended.
   var extend = function(protoProps, staticProps) {
@@ -1559,7 +1819,7 @@
 
     // The constructor function for the new subclass is either defined by you
     // (the "constructor" property in your `extend` definition), or defaulted
-    // by us to simply call the parent's constructor.
+    // by us to simply call the parent constructor.
     if (protoProps && _.has(protoProps, 'constructor')) {
       child = protoProps.constructor;
     } else {
@@ -1570,7 +1830,7 @@
     _.extend(child, parent, staticProps);
 
     // Set the prototype chain to inherit from `parent`, without calling
-    // `parent`'s constructor function.
+    // `parent` constructor function.
     var Surrogate = function(){ this.constructor = child; };
     Surrogate.prototype = parent.prototype;
     child.prototype = new Surrogate;
@@ -1598,11 +1858,11 @@
   var wrapError = function(model, options) {
     var error = options.error;
     options.error = function(resp) {
-      if (error) error(model, resp, options);
+      if (error) error.call(options.context, model, resp, options);
       model.trigger('error', model, resp, options);
     };
   };
 
   return Backbone;
 
-}));
+}));
\ No newline at end of file
diff --git a/vendor/assets/javascripts/underscore.js b/vendor/assets/javascripts/underscore.js
index 04cdc06..dfd89b2 100644
--- a/vendor/assets/javascripts/underscore.js
+++ b/vendor/assets/javascripts/underscore.js
@@ -1,4 +1,4 @@
-//     Underscore.js 1.8.2
+//     Underscore.js 1.8.3
 //     http://underscorejs.org
 //     (c) 2009-2015 Jeremy Ashkenas, DocumentCloud and Investigative Reporters & Editors
 //     Underscore may be freely distributed under the MIT license.
@@ -55,7 +55,7 @@
   }
 
   // Current version.
-  _.VERSION = '1.8.2';
+  _.VERSION = '1.8.3';
 
   // Internal function that returns an efficient (for current engines) version
   // of the passed-in callback, to be repeatedly applied in other Underscore
@@ -122,12 +122,20 @@
     return result;
   };
 
+  var property = function(key) {
+    return function(obj) {
+      return obj == null ? void 0 : obj[key];
+    };
+  };
+
   // Helper for collection methods to determine whether a collection
   // should be iterated as an array or as an object
   // Related: http://people.mozilla.org/~jorendorff/es6-draft.html#sec-tolength
+  // Avoids a very nasty iOS 8 JIT bug on ARM-64. #2094
   var MAX_ARRAY_INDEX = Math.pow(2, 53) - 1;
+  var getLength = property('length');
   var isArrayLike = function(collection) {
-    var length = collection && collection.length;
+    var length = getLength(collection);
     return typeof length == 'number' && length >= 0 && length <= MAX_ARRAY_INDEX;
   };
 
@@ -252,11 +260,12 @@
     return false;
   };
 
-  // Determine if the array or object contains a given value (using `===`).
+  // Determine if the array or object contains a given item (using `===`).
   // Aliased as `includes` and `include`.
-  _.contains = _.includes = _.include = function(obj, target, fromIndex) {
+  _.contains = _.includes = _.include = function(obj, item, fromIndex, guard) {
     if (!isArrayLike(obj)) obj = _.values(obj);
-    return _.indexOf(obj, target, typeof fromIndex == 'number' && fromIndex) >= 0;
+    if (typeof fromIndex != 'number' || guard) fromIndex = 0;
+    return _.indexOf(obj, item, fromIndex) >= 0;
   };
 
   // Invoke a method (with arguments) on every item in a collection.
@@ -480,7 +489,7 @@
   // Internal implementation of a recursive `flatten` function.
   var flatten = function(input, shallow, strict, startIndex) {
     var output = [], idx = 0;
-    for (var i = startIndex || 0, length = input && input.length; i < length; i++) {
+    for (var i = startIndex || 0, length = getLength(input); i < length; i++) {
       var value = input[i];
       if (isArrayLike(value) && (_.isArray(value) || _.isArguments(value))) {
         //flatten current level of array or arguments object
@@ -511,7 +520,6 @@
   // been sorted, you have the option of using a faster algorithm.
   // Aliased as `unique`.
   _.uniq = _.unique = function(array, isSorted, iteratee, context) {
-    if (array == null) return [];
     if (!_.isBoolean(isSorted)) {
       context = iteratee;
       iteratee = isSorted;
@@ -520,7 +528,7 @@
     if (iteratee != null) iteratee = cb(iteratee, context);
     var result = [];
     var seen = [];
-    for (var i = 0, length = array.length; i < length; i++) {
+    for (var i = 0, length = getLength(array); i < length; i++) {
       var value = array[i],
           computed = iteratee ? iteratee(value, i, array) : value;
       if (isSorted) {
@@ -547,10 +555,9 @@
   // Produce an array that contains every item shared between all the
   // passed-in arrays.
   _.intersection = function(array) {
-    if (array == null) return [];
     var result = [];
     var argsLength = arguments.length;
-    for (var i = 0, length = array.length; i < length; i++) {
+    for (var i = 0, length = getLength(array); i < length; i++) {
       var item = array[i];
       if (_.contains(result, item)) continue;
       for (var j = 1; j < argsLength; j++) {
@@ -579,7 +586,7 @@
   // Complement of _.zip. Unzip accepts an array of arrays and groups
   // each array's elements on shared indices
   _.unzip = function(array) {
-    var length = array && _.max(array, 'length').length || 0;
+    var length = array && _.max(array, getLength).length || 0;
     var result = Array(length);
 
     for (var index = 0; index < length; index++) {
@@ -593,7 +600,7 @@
   // the corresponding values.
   _.object = function(list, values) {
     var result = {};
-    for (var i = 0, length = list && list.length; i < length; i++) {
+    for (var i = 0, length = getLength(list); i < length; i++) {
       if (values) {
         result[list[i]] = values[i];
       } else {
@@ -603,42 +610,11 @@
     return result;
   };
 
-  // Return the position of the first occurrence of an item in an array,
-  // or -1 if the item is not included in the array.
-  // If the array is large and already in sort order, pass `true`
-  // for **isSorted** to use binary search.
-  _.indexOf = function(array, item, isSorted) {
-    var i = 0, length = array && array.length;
-    if (typeof isSorted == 'number') {
-      i = isSorted < 0 ? Math.max(0, length + isSorted) : isSorted;
-    } else if (isSorted && length) {
-      i = _.sortedIndex(array, item);
-      return array[i] === item ? i : -1;
-    }
-    if (item !== item) {
-      return _.findIndex(slice.call(array, i), _.isNaN);
-    }
-    for (; i < length; i++) if (array[i] === item) return i;
-    return -1;
-  };
-
-  _.lastIndexOf = function(array, item, from) {
-    var idx = array ? array.length : 0;
-    if (typeof from == 'number') {
-      idx = from < 0 ? idx + from + 1 : Math.min(idx, from + 1);
-    }
-    if (item !== item) {
-      return _.findLastIndex(slice.call(array, 0, idx), _.isNaN);
-    }
-    while (--idx >= 0) if (array[idx] === item) return idx;
-    return -1;
-  };
-
   // Generator function to create the findIndex and findLastIndex functions
-  function createIndexFinder(dir) {
+  function createPredicateIndexFinder(dir) {
     return function(array, predicate, context) {
       predicate = cb(predicate, context);
-      var length = array != null && array.length;
+      var length = getLength(array);
       var index = dir > 0 ? 0 : length - 1;
       for (; index >= 0 && index < length; index += dir) {
         if (predicate(array[index], index, array)) return index;
@@ -648,16 +624,15 @@
   }
 
   // Returns the first index on an array-like that passes a predicate test
-  _.findIndex = createIndexFinder(1);
-
-  _.findLastIndex = createIndexFinder(-1);
+  _.findIndex = createPredicateIndexFinder(1);
+  _.findLastIndex = createPredicateIndexFinder(-1);
 
   // Use a comparator function to figure out the smallest index at which
   // an object should be inserted so as to maintain order. Uses binary search.
   _.sortedIndex = function(array, obj, iteratee, context) {
     iteratee = cb(iteratee, context, 1);
     var value = iteratee(obj);
-    var low = 0, high = array.length;
+    var low = 0, high = getLength(array);
     while (low < high) {
       var mid = Math.floor((low + high) / 2);
       if (iteratee(array[mid]) < value) low = mid + 1; else high = mid;
@@ -665,11 +640,43 @@
     return low;
   };
 
+  // Generator function to create the indexOf and lastIndexOf functions
+  function createIndexFinder(dir, predicateFind, sortedIndex) {
+    return function(array, item, idx) {
+      var i = 0, length = getLength(array);
+      if (typeof idx == 'number') {
+        if (dir > 0) {
+            i = idx >= 0 ? idx : Math.max(idx + length, i);
+        } else {
+            length = idx >= 0 ? Math.min(idx + 1, length) : idx + length + 1;
+        }
+      } else if (sortedIndex && idx && length) {
+        idx = sortedIndex(array, item);
+        return array[idx] === item ? idx : -1;
+      }
+      if (item !== item) {
+        idx = predicateFind(slice.call(array, i, length), _.isNaN);
+        return idx >= 0 ? idx + i : -1;
+      }
+      for (idx = dir > 0 ? i : length - 1; idx >= 0 && idx < length; idx += dir) {
+        if (array[idx] === item) return idx;
+      }
+      return -1;
+    };
+  }
+
+  // Return the position of the first occurrence of an item in an array,
+  // or -1 if the item is not included in the array.
+  // If the array is large and already in sort order, pass `true`
+  // for **isSorted** to use binary search.
+  _.indexOf = createIndexFinder(1, _.findIndex, _.sortedIndex);
+  _.lastIndexOf = createIndexFinder(-1, _.findLastIndex);
+
   // Generate an integer Array containing an arithmetic progression. A port of
   // the native Python `range()` function. See
   // [the Python documentation](http://docs.python.org/library/functions.html#range).
   _.range = function(start, stop, step) {
-    if (arguments.length <= 1) {
+    if (stop == null) {
       stop = start || 0;
       start = 0;
     }
@@ -1048,6 +1055,15 @@
   // Fill in a given object with default properties.
   _.defaults = createAssigner(_.allKeys, true);
 
+  // Creates an object that inherits from the given prototype object.
+  // If additional properties are provided then they will be added to the
+  // created object.
+  _.create = function(prototype, props) {
+    var result = baseCreate(prototype);
+    if (props) _.extendOwn(result, props);
+    return result;
+  };
+
   // Create a (shallow-cloned) duplicate of an object.
   _.clone = function(obj) {
     if (!_.isObject(obj)) return obj;
@@ -1125,7 +1141,7 @@
     }
     // Assume equality for cyclic structures. The algorithm for detecting cyclic
     // structures is adapted from ES 5.1 section 15.12.3, abstract operation `JO`.
-    
+
     // Initializing stack of traversed objects.
     // It's done here since we only need them for objects and arrays comparison.
     aStack = aStack || [];
@@ -1276,11 +1292,7 @@
 
   _.noop = function(){};
 
-  _.property = function(key) {
-    return function(obj) {
-      return obj == null ? void 0 : obj[key];
-    };
-  };
+  _.property = property;
 
   // Generates a function for a given object that returns a given property.
   _.propertyOf = function(obj) {
@@ -1289,7 +1301,7 @@
     };
   };
 
-  // Returns a predicate for checking whether an object has a given set of 
+  // Returns a predicate for checking whether an object has a given set of
   // `key:value` pairs.
   _.matcher = _.matches = function(attrs) {
     attrs = _.extendOwn({}, attrs);
@@ -1516,7 +1528,7 @@
   // Provide unwrapping proxy for some methods used in engine operations
   // such as arithmetic and JSON stringification.
   _.prototype.valueOf = _.prototype.toJSON = _.prototype.value;
-  
+
   _.prototype.toString = function() {
     return '' + this._wrapped;
   };
@@ -1533,4 +1545,4 @@
       return _;
     });
   }
-}.call(this));
+}.call(this));
\ No newline at end of file