统一代码 都放到闭包中
修改gitignore
通过单元测试
Merge branch 'master' into 淇敼澹伴煶鍔犺浇

Conflicts:
	dist/yEngine2D.js
	dist/yEngine2D.min.js
	src/action/Sequence.js
	src/ySoundEngine/YSoundEngine.js