Refraction, reflection, and glass

- Addresses the remainder of Viktor's refraction feedback by establishing a range for the refraction value. -1 is maximum shrinking of the refraction image, 0.0 is no change, 1.0 is maximum magnification.
- Add CCEffectReflection.
- Add CCEffectGlass which combines both refraction and reflection.
- Address a few low hanging performance issues in CCEffects that were uncovered by Instruments.
Okay. The way I remembered it was that I introduced the push/pop to aid in debugging the corresponding GL calls but maybe the push/pop was already there. First I fixed debug label creation (doing it ahead of time and storing it in CCEffectRenderPass instead of doing it repeatedly on the fly) but then I still saw that push/pop was fairly expensive so I switched to the macros.

Thanks for pointing out the issue. I'll dig further into it.