Cleaning up Clear methods in CCDrawManager:
Cleaning up Clear methods in CCDrawManager:

* chaining methods
* when clearing depth buffer we should be using 1.0f which sets the buffer to the furthest depth

hig-ag/CocosSharp,haithemaraissia/CocosSharp,zmaruo/CocosSharp,mono/CocosSharp,MSylvia/CocosSharp,mono/CocosSharp,haithemaraissia/CocosSharp,MSylvia/CocosSharp,zmaruo/CocosSharp,TukekeSoft/CocosSharp,TukekeSoft/CocosSharp,hig-ag/CocosSharp