- Added the fuzziness slot to ReplaceColorNode and ColorMaskNode. It works like
the fuzziness parameter in Photoshop that gives softer edges to the mask.
- Changed the output format of ColorMaskNode from Vector3 to Vector1. It only
outputs single channel masks.
- Added the opacity slot to BlendNode. It's useful when one tries using
BlendNode like layers in Photoshop.