Allow hooking into VBR calls

I'm kinda shooting in the dark here, but I tried this on my local copy and it worked well. Please pull this if it seems correct.

Also added `self` call at the end since I needed to do that to expose Lame to other webworkers.

post.js

@@ -29,6 +29,21 @@ return {
 
 	set_bitrate: Module.cwrap('lame_set_brate', 'number', [ 'number', 'number' ]),
 	get_bitrate: Module.cwrap('lame_get_brate', 'number', [ 'number' ]),
+
+	set_VBR: Module.cwrap('lame_set_VBR', 'number', [ 'number', 'number' ]),
+	get_VBR: Module.cwrap('lame_get_VBR', 'number', [ 'number' ]),
+
+	set_VBR_q: Module.cwrap('lame_set_VBR_q', 'number', [ 'number', 'number' ]),
+	get_VBR_q: Module.cwrap('lame_get_VBR_q', 'number', [ 'number' ]),
+
+	set_VBR_mean_bitrate_kbps: Module.cwrap('lame_set_VBR_mean_bitrate_kbps', 'number', [ 'number', 'number' ]),
+	get_VBR_mean_bitrate_kbps: Module.cwrap('lame_get_VBR_mean_bitrate_kbps', 'number', [ 'number' ]),
+
+	set_VBR_min_bitrate_kbps: Module.cwrap('lame_set_VBR_min_bitrate_kbps', 'number', [ 'number', 'number' ]),
+	get_VBR_min_bitrate_kbps: Module.cwrap('lame_get_VBR_min_bitrate_kbps', 'number', [ 'number' ]),
+
+	set_VBR_max_bitrate_kbps: Module.cwrap('lame_set_VBR_max_bitrate_kbps', 'number', [ 'number', 'number' ]),
+	get_VBR_max_bitrate_kbps: Module.cwrap('lame_get_VBR_max_bitrate_kbps', 'number', [ 'number' ]),
 
 	encode_buffer_ieee_float: function(handle, channel_l, channel_r) {
 		var outbuf = _malloc(BUFSIZE);
@@ -65,3 +80,6 @@ return {
 
 })();
 
+self.Lame = Lame; // make Lame accessible to other webworker scripts.
+
+