background music

public domain music from http://mcs.franknora.com/

First 2 minutes of New Midnight Cassette 20 - Manga (2012)

https://github.com/ugly-potato-guy/potato-tap/issues/33
Merge conflict PlayScreen
Merge remote-tracking branch 'origin/master'

Conflicts:
	core/src/com/github/uglypotatoguy/screens/PlayScreen.java
	core/src/com/github/uglypotatoguy/screens/play/DeathOverlayScreen.java
Merge remote-tracking branch 'origin/master'