Restore MediaPlayer song and position after resume on WP8
Removed leftover WP8 code
Some more cleanup in MediaPlayer
Null checks for _mediaElement in handlers.
Merge pull request #2 from dancrevier/wp8_mediaplayerresume

Null checks for _mediaElement in handlers.
Merge pull request #1633 from Nezz/wp8_mediaplayerresume

MediaPlayer app resume support on WP8