Issue #5703: Add customwidget support
Issue #5703: Add customwidget support
Issue #5703: Add customwidget support
Issue #5704: modify codes for Cocos UI works well.
Merge pull request #2003 from VisualSJ/develop-gui

Issue #5703: Add customwidget support
Issue #5704: reformat some functions of ccui.TextField
Merge branch 'develop' of https://github.com/cocos2d/cocos2d-html5 into Iss5704_CCUIPreformance