Merge changes from topic 'directoryfragment-stable-ids'

* changes:
  Wrap up the stable ID refactor.
  Re-enable sorting in the DirectoryFragment.
  Fix file deletion after the move to Model IDs.
  Transition selection to use Model IDs.
  Switch DirectoryFragment code to use model IDs.
tree: 82fad2977b68bda7a023c41f449495afbc4c27aa
  1. res/
  2. src/
  3. tests/
  4. Android.mk
  5. AndroidManifest.xml
  6. wrap_alpha.py