Merge branch 'Game-Center' of https://github.com/GunTeam/ScribbleStroids into Levels

Conflicts:
	ScribbleStroids.spritebuilder/GameScene.h
	ScribbleStroids.spritebuilder/GameScene.m
	ScribbleStroids.spritebuilder/ScribbleStroids.xcodeproj/project.pbxproj
	ScribbleStroids.spritebuilder/Source/MainScene.h
	ScribbleStroids.spritebuilder/Source/MainScene.m
	ScribbleStroids.spritebuilder/SpriteBuilder Resources/GameScene.ccb
	ScribbleStroids.spritebuilder/SpriteBuilder Resources/MainScene.ccb