Merge pull request #1837 from dingpinglv/Iss3943_ActionAPI

Issue #3943: refactoring cc.EaseAction for use friendly
Issue #3943: Add the cc.action.speed method
Merge branch 'develop' of https://github.com/cocos2d/cocos2d-html5 into develop-3943-2
Issue #3943: Moving the cc.action.speed method
Merge pull request #1838 from VisualSJ/develop-3943-2

Issue #3943: Add the cc.action.speed method
Issue #3943: add a reverse sample function to cc.easeElasticOut
Merge branch 'develop' of https://github.com/cocos2d/cocos2d-html5 into Iss3943_ActionAPI