Refactored CCEffectGaussianBlur, it can now support a varying pixel blur size.
Made sigma adjust with specified pixel blur size.
Refactored glow effect (now called bloom). Added the ability specify pixelblurRadius and also a glow intensity.
Added a luminance threshold to the bloom effect.
Cleaned up luminance logic in bloom effect.
Merge remote-tracking branch 'upstream/develop' into develop

Conflicts:
	cocos2d-ui-tests/tests/CCEffectsTest.m
Corrected param names in CCEffectGaussianBlur.
Merge pull request #865 from osinoleg/develop

Refactored blur and bloom effects.