Merge pull request #897 from thayerandrews/develop

Refraction, reflection, and glass
CCEffectsTest - Add the latest effects to the performance test
CCEffectTest - Add a stacking test
CCEffects - Fix stacking of refraction, reflection, and glass

These were all directly reading cc_MainTexture and combining it with cc_FragColor within their
function bodies instead of putting this into their input snippets.  In simpler terms this means that
input values from previous effects were not being used.
Added a keyExists method to CCCache
Added CCCache test
Minor CCResponder design cleanup
CCEffectReflection - Add initializer / constructor methods that accept fresnel parameters
CCEffectsTest - Fix stacking test name
CCEffects - Misc cleanup - No functional change

- Correct case of CCTexture.h in a #import
- Replace badly copy-pasted ;; with ;
- Remove some trailing whitespace
CCEffects - Privatize most of the CCEffects API

For the 3.2 release we only want to expose the effects we've implemented so far and not the internal
effect framework. To this end, move most of the internal stuff that had been in CCEffect.h to CCEffect_Private.h.
CCEffectGlass - Remove misplaced semicolon
Merge branch 'thayer/effectApiPrivatization' into develop
CCEffects - Move effect includes from CCEffectNode.h to cocos2d.h
CCEffects - Remove CC_ENABLE_EXPERIMENTAL_EFFECTS
Merge remote-tracking branch 'upstream/develop' into develop