Persistence in mapped songs

Persistence now implemented in application, for mapped files only; not
for edit values. Some necessary performance gains have been implemented.
More performance gains may be needed, especially at startup and
shutdown.

Additional changes include:
Tap gesture has less lag, but is more sensitive.
I took out the background. No offence but please don't put it back
unless most of the group disagrees with this decision :/
All threads are safely exited on application pause.
Threads will yield time more often when they are not playing.
FileOrRes is immutable? Don't know why I did this.
Added plenty of useless System.out.println calls!
Threads now limit priority when not in use

Further performance gains achieved by having threads limit their own
priority when idle.
Startup time improved

Threads now also limit their priority while waiting for the application
to start up.
Edit songs while they play

Now you can balance by ear if you want!
Ryan: Song selection modified

All of the default songs should now have the same bpm and there are also
more of them
Clip edits now persist
Song information display

Tell me if you guys like/don't like this. We can revert this junk if you
guys don't like it.
Took out some test text
Merge remote-tracking branch 'origin/Persistence' into dev

Conflicts:
	BeatMatrix/gen/com/joshuac/beatmatrix/R.java
	BeatMatrix/res/values/colors.xml
	BeatMatrix/src/com/joshuac/beatmatrix/ButtonMatrix.java