- add Settings: Activity to start / stop MPD Service (Main).
- Main is a service that run in foreground with a notification. See
Service.startForeground documentation for more details.
- Main.Client is used to control the service: start or stop it and also receive
callbacks when service encounters an error, is killed, is started or is
stopped.
- Main.start to start the service without any fallback.
Thomas Guillem