Only forward touch events if CCResponder has user interaction enabled

With the current implementation touch events caused by an active touch will be forwarded to a `CCResponder` even if the responder sets `userInteractionEnabled` to `NO`. 

Can be reproduced with the following sequence:

- Start touch
- Set `userInteractionEnabled`to `NO`
- Move touch

With the current implementation `touchMoved` would be called in the above example. 
With the suggested change a touch event will only be forwarded if a node has `userInteractionEnabled` set to `YES`.