Issue #4277: update reference of submodule 'cocos2d-html5'
Merge branch 'master' of https://github.com/cocos2d/cocos2d-js into Iss4277_ReleaseV3.0
Merge pull request #58 from dingpinglv/Iss4277_ReleaseV3.0

Issue #4277: update reference of submodule 'cocos2d-html5'
Merge branch 'master' of https://github.com/cocos2d/cocos2d-js
Issue #4277 : Change some apis to private.
Issue #4294 : Add LoaderTest and PathTest into js-tests.
Bind some api about constants into jsb.