Bug 1104003 - [Loop][Rooms] Create basic 'room' screen

See bug https://bugzilla.mozilla.org/show_bug.cgi?id=1104003 please. Action happens at https://github.com/jaoo/firefoxos-loop-client/tree/1104003.
When removing handlers, clean all cached info (for example https://github.com/mozilla-b2g/firefoxos-loop-client/pull/337/files#diff-405ccd9a75fe7de989c2a6e90559656bR17)