https://github.com/imageworks/OpenColorIO/pull/157

Updated much of the serialization code to log warnings when unknown
tokens are encountered. Also, updated MatrixTransform to expose
separate get/set accessors for matrix vs. offset. Suitable for 1.0 /
0.8 (this will ensure parsing code is identical between versions, as
is desired).

Addresses issues:
https://github.com/imageworks/OpenColorIO/issues/146
https://github.com/imageworks/OpenColorIO/issues/152

-- Jeremy