Fix some bugs
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
Merge pull request #1605 from pandamicro/develop-3.0

Fix some bugs and Update samples