Issue #4713: fix a bug of cc.eventManager that the dirty flag of parent node's children are invalid when the parent hadn't add to eventManager
Merge branch 'develop-3.0' of https://github.com/cocos2d/cocos2d-html5 into Iss4713_SyncEventManager
Closed #4713: Sync cc.eventManager and cc.ScrollView to -x v3.0 Stable
Merge branch 'develop-3.0' of https://github.com/cocos2d/cocos2d-html5 into Iss4713_SyncEventManager
Merge pull request #1758 from dingpinglv/Iss4713_SyncEventManager

Closed #4713: Sync cc.eventManager and cc.ScrollView to -x v3.0 Stable