describe story of AV-GSG
Merge pull request #1 from vnoc-YeZi/YeZi

describe story of AV-GSG
+ 场景管理器和场景基类
Merge branch 'master' of https://github.com/zpublic/AV-GSG into Sum_Branch

Conflicts:
	AV-CSG/AV-CSG.vcxproj
	AV-CSG/AV-CSG.vcxproj.filters