Issue #35: Add Able Remote support for playback on TV.

This moves the preferences around, but more importantly adds initial support
for using Able Remote to play back a video on the TV.  Future versions may
interface with the Anymote protocol directly and only launch able for
video controls.  It is out of scope for Serenity to provide full video
remote controls currently.

There is some code to try and get Serenity to be a player for Able but
it currently isn't responding to the appropriate intents.
Performance Enhancements to Gallery

Use a custom gallery based on some changes from the EcoGallery.  This
provides a couple of advantages:

1. Views are now recycled and the bin isn't cleared every time.
2. Less Garbage collection which means better app performance.

Movie and Episode browsers are now using the new Gallery View.