Cleaned up project files, configurations, and solution configurations.
Removed MultiTrackMMLPlayer.Loop; this snuck in in a large pull request and never should've been there, as the property had no functionality within the player. The correct way to implement such a property would have been to add it to a subclass of the MultiTrackMMLPlayer.
Also replaced DateTime.Now for default timing with MusicPlayer.Time which uses a Stopwatch instance for improved resolution. The MusicPlayer.Time property locks around access of the Stopwatch instance, and is thread-safe.