CCBReader compatibility changes for Sprite Kit

Conflicts:
	cocos2d-ui/CCBReader/CCBReader.m

I cherry-picked all my recent commits for CCBReader because it seemed none of them have been integrated yet.

The nodeFromClassName: method in CCBReader.m is fundamental for SK reader to work. The method is overridden to provide mapping from CC or editor class names to actual SK class names and while doing so also run custom init (ie SKSpriteNode with color won't work if it's created with just alloc/init, it has to be created with the color:size: initializer).