issue #3353:Lua gc mechanism will make the extended attributes of lua userdata disapper
Merge branch 'master' of https://github.com/cocos2d/cocos2d-x into master_cocostudio
issue #3374:Register the lua manual binding funtions leading to change the top index of lua state
Merge branch 'master' of https://github.com/cocos2d/cocos2d-x into master_cocostudio
Merge pull request #4443 from samuele3hu/master_cocostudio

issue #3353:Lua gc mechanism will make the extended attributes of lua userdata disappear