Fixing a number of bugs
- Fixing issue 32
- Fixing issue 33
- Adding a better BaseCastManager.clearContext() variation
- Implementing enhancement 30
- Making sure play/pause button is hidden when ProgressBar is shown in VideoMediaRouteControllerDialog
- probably some more adjustments and bug fixes
Clearing cached session if when disconnecting
Merge branch 'master' of https://github.com/googlecast/CastCompanionLibrary-android

Conflicts:
	src/com/google/sample/castcompanionlibrary/widgets/MiniController.java