Add level music

Signed-off-by: xclam <romain.rj@gmail.com>
Fire the Foe exit event properly

Signed-off-by: xclam <romain.rj@gmail.com>
Adding mute button in the hud

Signed-off-by: xclam <romain.rj@gmail.com>
Merge branch 'music'

Conflicts:
	age-of-tower/src/com/nsx/ageoftower/screen/GameScreen.java
	age-of-tower/src/com/nsx/ageoftower/utils/Foe.java

Signed-off-by: xclam <romain.rj@gmail.com>