issue #82: adding tri-state property, changing RepeatMode constants to be all-caps. simplifying getNextState() logic.
issue #82: removing unnecessary MAX usage
making RepeatMode[] vals static final
issue #82: preliminary refactor to make MediaPlayer use MediaSource array (instead of list) and some other refactors required before adding 3rd type of replay mode
issue #82: Merge branch 'issue82_RepeatSong' into 5.5.3