CCButtons now utilize Float opacity instead of int opacity.
Merge branch 'develop-v3' of https://github.com/cocos2d/cocos2d-iphone into develop-v3
Fixes issue with color interpolation
Renames interpolation method in CCColor
Merge branch 'develop-v3' of https://github.com/cocos2d/cocos2d-iphone into develop-v3