CCEffectNode - Fix a bunch of sizing issues and add tests for them

- Refactor CCRenderTexture's create method into create and createTextureAndFboWithPixelSize. In CCEffectNode, override the create method so pixel size is computed correctly. This fixes effect node's parent relative sizing while leaving render texture the same (because render texture needs even more changes that I don't want to tackle right now).
- Override setContentSizeType on effect node so it also marks the content size as dirty when it changes.
- If content size has changed since the last visit, destroy any allocated resources and recreate them (as CCRenderTexture already does).
- Pass the content size in points to CCEffectRenderer from sprite and effect node.
- Add a bunch of effect node sizing tests.
The problem is that the "auto-draw" functionality is pretty rarely used I think. Personally, I never noticed it until I was rewriting the class for 3.1. Before that I'd never heard it come up in the forums for instance. CCRenderTexture is primarily used by calling the begin/end methods explicitly from outside of a draw method, usually in update, and often only when content changes.

SpriteBuilder doesn't let you explicitly set the content size/type of a CCSprite. I'm not really sure what would happen if you did it in code. It probably makes as much (or as little?) sense for CCRenderTexture as well.