First attempt at fragments up and running.
Got the hang of fragment navigation, experimenting with
TimelineFragment.
Started a TrackView, and added it to the TimelineFragment along with
expandable buttons.
Got the timeline fragment, main activity, and AudioSystem talking.
Removed old activity code which is no longer needed.
Cleaned up some resources which were also no longer necessary.
Added method for generating a waveform, or series of highest
and lowest points, from a Track at a specified resolution.
Added some getters and setters to TrackView.