Merge branch 'Developer' of https://github.com/CienProject2014/OneLevelHero into newyr
#13
#13 CollectionScreen backButton까지
Merge remote-tracking branch 'origin/yr' into Developer

Conflicts:
	core/build.gradle
	core/src/com/mygdx/resource/Scene.java
	core/src/com/mygdx/screen/MenuScreen.java