Unify Web, iOS and Android repos (was: Build iOS and Android from the same Cordova config file)

[ghost]

Instead of forking, let's intelligently build Hive from one repository with config files appropriate to the platform. See hivewallet/hive-ios#42

[weilu]

What's the benefit of moving everything into the same repo? Even if you move everything under the same repo, they'd still need to stay in different branches. At least where we stand now when a ticket is filed we know which version of hive it is for.