Add some optimizations, comments, do some refactoring

Use Bitmap.Config.RGB_565 in our BitmapFactory.Options config to be
reduce memory footprint since we don't need the alpha channel.

Add some comments, do some refactoring.
Update wallpaper description.
Remove unused settings activity
Make checkstyle happy
Update app version to 1.1
[maven-release-plugin] prepare release lanterns-live-wallpaper-parent-1.1