Merge pull request #1601 from pandamicro/develop-3.0

Refactor #4126: Make override properties automatically in extend function
Issue #3427: Delete all of old event handler and dispatcher
Merge pull request #1603 from dingpinglv/Iss3427_NewEventDispatcher

Issue #3427: Delete all of old event handler and dispatcher
Fix some bugs
Issue #3427: remove keyboard file from moduleConfig.json
Merge branch 'develop-3.0' of https://github.com/cocos2d/cocos2d-html5 into Iss3427_NewEventDispatcher
Merge pull request #1604 from dingpinglv/Iss3427_NewEventDispatcher

Issue #3427: remove keyboard file from moduleConfig.json
Update samples
Merge branch 'develop-3.0' of https://github.com/cocos2d/cocos2d-html5 into develop-3.0

# By dingpinglv
# Via dingpinglv
* 'develop-3.0' of https://github.com/cocos2d/cocos2d-html5:
  Issue #3427: remove keyboard file from moduleConfig.json
  Issue #3427: Delete all of old event handler and dispatcher