Officially support `opacity` in ColorLayer and ImageLayer.
Officially support `opacity` in ColorLayer and ImageLayer.

Smoss/Enoru-eco,srbala/melonJS,melonjs/melonJS,gopalindians/melonJS,gopalindians/melonJS,gopalindians/melonJS,MarkoIvanetic/melonJS,melonjs/melonJS,MarkoIvanetic/melonJS,rlugojr/melonJS,srbala/melonJS,TukekeSoft/melonJS,Smoss/Enoru-eco,TukekeSoft/melonJS,rlugojr/melonJS,rlugojr/melonJS,TukekeSoft/melonJS,srbala/melonJS