Creation of Button Class
Revision of level backgrounds
Final Background Added
Sounds for all enemies, creation of SoundManager class and refresh of
explosions
Creation of explosion sound
Test Change
Merge remote-tracking branch 'origin/master' into Spencer-working

Conflicts:
	prometheus/src/com/strikeIT/prometheus/Enemy.java
	prometheus/src/com/strikeIT/prometheus/GamePlay.java
Merge branch 'Spencer-working' of
https://github.com/Vader19695/CSC122Game3 into Spencer-working

Conflicts:
	.gitignore