MPDroidService: Move album cover updating to it's own class.
NotificationHandler: Construct the notification, update incrementally.
NotificationHandler: Simplify the activity starting pending intent.
NotificationHandler: Remove the callback, use an instance to set foreground.
RemoteControlClientHandler: Move the seekbar code to it's own class.
RemoteControlClientHandler: Split track cover update to it's own method.
MPDroidService: Improve focus code.
Service: Try a shorter timeout.

It's really subjective. 10 minutes seems a bit too long, a few minutes too
short. Try 5 minutes / 5 minutes 30 seconds.
Service: Use a singular handler with 'what' messages.