Merge pull request #422 from avuton/master

StreamService & various warning cleanup
Use GraceNote for covers only if the user set one.
- Request quota exceeded for the shared gracenote ID.
- Fix a NPE in covermanager
PhoneStateReceiver: Clean up import order.

In accordance with Google's code style guidelines, Android's libraries should
be imported first, then third party, the Java imports.

Of course, it's not a requirement, but it's good for readability.