update .gitignore for android-studio
Code cleanup after bugfix in Track.java
Cleanup prompted by pull request from ortylp
fix missing audio chunk at the end of file
Merge branch 'cleanup'

Conflicts:
	src/com/falconware/prestissimo/Track.java
Merge branch 'upstream' of https://github.com/ortylp/Prestissimo into ortylp-upstream

Conflicts:
	src/com/falconware/prestissimo/Track.java
Added a few locks around contentious resources and call the onCompletion callback in a new thread.