Sprites

Created new sprites for explosions
Updated AnimationState enum with more advanced functionality
Explosions

Enemies and the fighter now explode when destroyed
Tweaks
Merge branch 'feature-explosion' into develop
Merge branch 'feature-explosion' into develop

Conflicts:
	bin/Galaga/Fighter.class
	bin/Galaga/Galaga.class
	src/Galaga/Fighter.java
	src/Galaga/Galaga.java
I may have fucked up
I think I definitely fucked up