Tween Enhancments

@ndonald2 I added a few things to expanding our tweening capabilities.  Let me know what you think.
Color can totally be supporting using NSValue wrapping a simple struct:
http://stackoverflow.com/questions/4516991/whats-the-best-way-to-put-a-c-struct-in-an-nsarray

NSValue is really underappreciated for how many gaps it bridges from pure c.