Fixed twitter icon visibility.
Finished base implementation of InputManager.
Added SceneManager and ARManager protos. Enhanced other modules. Cleaned main.js further.
Enhanced ARManager. It now finds specific XFlow tags from index and creates observers for them. More generalisation is needed later, so developers can create custom observers more easily.
Added 'use strict' for WeXAr lib files. Fixed some problems with firefox nightly for android. Tested drawing video on texture in webgl context; left test code commented out in index for further testing.
Added new encountered bugs in TODO.md
Updated formatting.