Merge pull request #2456 from pandamicro/next

Fixed #15: Supported local file loading with Brackets
#19: Support property registration and add properties in base nodes
#19: Polish property defines
#20: Refactor cc.Node to support serialization
#20: Refactor cc.Layer s to support serialization
#20: Refactor cc.Sprite to support serialization
#20: Refactor cc.LabelTTF to support serialization
#20: Improve cc.Class implementation
#20 Improve serialization and addProperty
#22: Fix end issues in cc.director
#22: Support pause and restart in framework
And added a loadScene alias function