Theme Chooser: Initial Contribution [1/2]

Introduces a new theme chooser UI for the new theme engine.
The new theme chooser allows the user to mix'n'match
theme components (styles, boot anim, icons, fonts, wallpapers, sounds).

Contributors:
  Adrian Foulk - UX Lead
  Andrew Mast - Software Engineer
  Clark Scheff - Software Engineer
  RJ Oakes - QA Engineer

Special thanks to T-Mobile for open sourcing the original theme engine.

Change-Id: I59aab2a262314962c2034eb36044564acec769a1