#51 [완성]Screen Manager 완성. (game을 인자로 받지 않기 떄문에 game. 을 사용하는 것들 수정이 필요)
Merge branch 'Developer' into #51_ScreenManager_만들기

Conflicts:
	core/src/com/mygdx/game/OneLevelHero.java
	core/src/com/mygdx/resource/GameUi.java
	core/src/com/mygdx/screen/CreditScreen.java
	core/src/com/mygdx/screen/LoadScreen.java
	core/src/com/mygdx/screen/PrologueScreen.java
	core/src/com/mygdx/screen/VillageScreen.java
	core/src/com/mygdx/screen/WorldMapScreen.java
	core/src/com/mygdx/util/LoadLauncher.java