little fix
small fixes in README.md
Improves GLProgram and ShaderCache API for JSB
cocos2d GL function fixes:

Instead of: "gLSomething" -> "glSomething"
cocos2d enums: better generation

__ is replaced with _
"program" functions accepts numbers as well
Improves function/method naming convention:

All JSB related functions start with "JSB_". No exceptions.
All jsval_to and  _to_jsval conversion functions have the following convention:
  JSB_jsval_to_XXX()
  JSB_jsval_from_XXX()
Updates CHANGELOG