CCEffectsTest - Add test of effects and sprite colors / opacity
CCEffectsTest - Add another stacking test for sprite color / opacity + effects

Leave stitching enabled on the stack but disable it after the second effect. This means our stack [A, B, C]
becomes [ AB, C ] instead of [ ABC ] which is another good case to test.
CCEffects - Fix mixing of sprite color / opacity with effects

Some effects handled colors and opacity properly, some did not. And none of them did the
right thing if multiple effects were stacked together without stitching. Color would either be
multiplied in multiple times or not at all.

This change introduces a new code snippet for effect function inputs that is used if the effect
function is the first one in a stack. Otherwise, the alternative snippet is used. The initial snippet
for all effects multiplies the fragment color by the texture and the alternate snippet just fetches
the texture.

In plain english this means that the input to an effect stack is the sprite's texture times its color
and we insure that the texture times color multiply does not happen again in the stack.
CCEffectsTest - Add test of effect node parent resizing
CCEffectNode - More parent relative sizing fixes

Keep track of the last allocated content size and compare this to the current content size.
If the two are different, destroy and reallocate the associated texture and FBO. This fixes
cases where the effect node's size is parent relative (and does not change) but the parent's
size does change.
CCEffects - Explicitly set the strong and assign property attributes

Bill and Scott have pointed out that the absence of these attributes cause warnings in non-ARC code.
CCEffectStack - Fix shader uniform management

This wasn't causing any problems yet but shader uniforms for effect stacks were not being
handled properly under all circumstances. After name mangling, the old code would construct
a uniform dictionary that was never used at render time. By render time, the effects would just
receive the default uniform dictionary from CCNode.
CCEffectStack - Add some comments to the stitching code - No functional change