Issue #5704: fixed a typo of ccui.Widget that rename _hitted to _hit
Issue #5704: refactor cc.Widget
Issue #5704: modify "onSizeChanged" to "_onSizeChanged"
Issue #5704: rename "initRenderer" to "_initRenderer"
Issue #5704: rename some function from "public" to "protected"
Issue #5704: add some jsDoc document to ccui.Layout
Issue #5704: refactor ccui.LayoutManager for better performance.
Fixed #3546: fixed a bug of cc.Layer,cc.LayerColor
Issue #5704: refactor cc.Layout
Merge branch 'develop' of https://github.com/cocos2d/cocos2d-html5 into Iss5704_CCUIPreformance
Issue #5704: sync ccui.HBox, ccui.VBox, ccui.RelativeBox
Issue #5704: refactor ccui.PageView for better performance.
Issue #5704: remove the unused codes.
Merge branch 'develop' of https://github.com/cocos2d/cocos2d-html5 into Iss5704_CCUIPreformance
Issue #5704: sync ccui.Widget, ccui.Button, ccui.CheckBox
Merge branch 'develop' of https://github.com/cocos2d/cocos2d-html5 into Iss5704_CCUIPreformance
Issue #5704: CCUIPreformance
UILoadingBar
UIRichText
UISlider
UIText
UITextAtlas
UITextBMFont
UITextField
Issue #5704: Fix bugs
Issue #5704: sync ccui.ScrollView and ccui.ListView
Merge branch 'develop' of https://github.com/cocos2d/cocos2d-html5 into Iss5704_CCUIPreformance