Made boss level possible (!)
Added UpgradeItem class
Merge branch 'UpgradesSystem'
Undid fail
Fixed minor problems
Made alien of any size turn around effectively at the edge of the screen

Fixed errors with button handling
Merge branch 'master' into BossAlien

Conflicts:
	SpaceInvadersEPIC/bin/spaceInvaders/Game$KeyInputHandler.class
	SpaceInvadersEPIC/bin/spaceInvaders/Game.class
	SpaceInvadersEPIC/src/spaceInvaders/bossAlien.java