Adding test messagest!

Test messages for use with file source
More testing of messages

Update to use two diff files, start PB on first, que second
Playback changes

Updating to change how we handle messages from a messenger (que on own thread)
Change behavior of MPlayer to quit on exit, this change needs to be reviewed.
Fixes for continous playing

It now iterates over the next song in the playlist!!!!!!!
Merge branch 'dev' of https://github.com/mindstorms6/pi_audio into dev
Merge pull request #7 from mindstorms6/dev

Dev