UI and Controller Updates

- The search function was tested but it did not work with an ArrayList
of Song objects.
- The action bar was implemented with its controllers.
- Single selection was tested with the correct results however multiple
selection has not been tested.
- Stub classes for the Scanner and Song classes were implemented.
- The MediaRetriever object did not work as expected.
- Classes that contained "MainScreen" were refactored to "MyMusic"
- Minimum SDK version was changed to 14(Ice Cream Sandwich 4.0.3)