Safe onDestroy(). Fixes #528
NotificationService: Don't rely on RCC for state updates.

Because we're using more than two states for RemoteControlClient we no longer
get an accurate play/pause state. Fixes #526.
NotificationService: Remove unused check for title.
NotificationService: On reconnection, update status.

This is good for now and will be improved upon later.
MainMenuActivity: Replace System.exit() with finish().
NotificationService: Ensure StreamingService was starting NotificationService.

When RemoteControlReceiver was opening NotificationService, NotificationService
was assuming StreamingService started it. This caused bug #526.
MainMenuActivity: Hard disable services after stop.
NotificationService: When opened by an unknown intent, log and stopSelf().
GracenoteCover: Remove possible errand null assignment before check for null.
RemoteControlReceiver: Cleanup and reuse code.
MPDroid: Fix some misplaced listener cleanups.
NotificationService: Pause on ACTION_AUDIO_BECOMING_NOISY on localhost as well.
ConnectionSettings: Default to server on localhost.

We can't really default to anything else until mDNS support is added, use
localhost.
StreamingService: Set wake lock for mediaPlayer, rather than the service.
NotificationService: Simplify the onStartCommand server commands/audio focus.
NotificationService: Fix some warnings.
NowPlayingFragment: Use volumeChanged() to toggle volume bar visibility.
dmix: Add/update copyrights, add to IDEA.
MPDStatus: Add mixRampDelay status entry.
RemoteControlReceiver: Add some interesting logs to assist debugging.