move CCActionEaseEx and CCTweenFunction to core engine
move CCActionEaseEx content to CCActionEase
rename namespace of CCTweenFunction to cocos2d and fix some compile errors
refactor EaseIn with CCTweenFunction
change CCTweenFunction class to tweenfunc namespace
remove unused std::function declare
refactor easeIn, easeOut and easeInOut, elastic, bounce, back, quartic etc with free tween functions

finish refactor all ease action with tween functions
add tests of all the new added CCActionEaseEx in CCActionEase
fixed #3620. merge cocostudio/CCActionXXX to CCAction