[Bf-codereview] Chroma Matte Node (issue 5534067)

[dfelinto at gmail.com]

Reviewers: bf-codereview_blender.org,

Description:
honestly speaking I still need to double check the operator code itself.
(will do it later today, although I think it's correct).

But apart from that the code should be reviewable now.
[and I never used this node in my life, may need help to test it, but
that can be after all mattes are done]

Please review this at http://codereview.appspot.com/5534067/

Affected files:
   source/blender/compositor/CMakeLists.txt
   source/blender/compositor/intern/COM_Converter.cpp
   source/blender/compositor/nodes/COM_ChromaMatteNode.cpp
   source/blender/compositor/nodes/COM_ChromaMatteNode.h
   source/blender/compositor/operations/COM_ChromaMatteOperation.cpp
   source/blender/compositor/operations/COM_ChromaMatteOperation.h