CM11 Themes: remove handleThemeConfigChanges

This was used by the T-Mobile theme chooser and is no longer
needed with the new chooser.

Change-Id: I035606ffe6cb3efc82a3a0ce79215509d8289503
WallpaperPicker: Destroy cropview to avoid leaks

If the cropview's TiledImageRenderer is rendering threads, the activity
context gets leaked. Avoid that by invoking its destroy in onDestroy() of activity.

Change-Id: I0804c903d14d3f3d13529f0fe90d12784d97e93f