Added some sounds playing in the background
A new sound
Fixed bug not playing sound on android
New .apk
Changed function name
Merge branch 'sound' into develop

Conflicts:
	zombie-world-android/bin/classes.dex
	zombie-world-android/bin/resources.ap_
	zombie-world-android/bin/zombie-world-android.apk
	zombie-world/src/se/glory/zombieworld/screens/GameScreen.java