Improved background music and graphics

- New song
- You can actually pause and resume the song in any activity (it used to
stop and restart)
- Made the pop-ups menus more responsive
- Some other graphical changes
Merge branch 'master' of https://github.com/elopez1/puzzle15

Conflicts:
	bin/AndroidManifest.xml
	bin/PuzzleActivity.apk
	bin/classes.dex
	bin/resources.ap_
	gen/edu/harding/puzzle15/R.java
	src/edu/harding/puzzle15/PuzzleClassicalBoard.java
	src/edu/harding/puzzle15/PuzzlePictureActivity2.java
Merge branch 'master' of https://github.com/elopez1/puzzle15

Conflicts:
	bin/AndroidManifest.xml
	bin/PuzzleActivity.apk
	bin/classes.dex
	bin/resources.ap_
	gen/edu/harding/puzzle15/R.java
	src/edu/harding/puzzle15/PuzzleClassicalBoard.java
	src/edu/harding/puzzle15/PuzzlePictureActivity2.java