Changed byte code file ext to ".jsc"

Modified loading logic to load js file first

Conflicts:
	scripting/javascript/bindings/ScriptingCore.cpp
	tools/jsbcc/src/main.cpp
Trivial
Merge branch 'cocos2d-x-2.1.1' of https://github.com/sunzhuoshi/cocos2d-x into cocos2d-x-2.1.1