CxF support - ignore parts of CxF where there already exist solutions particular to our industries

[JGoldstone]

The CxF Profile feature for device-space-to-device-space color conversion sure feels a lot like something OpenColorIO already does well.

I admit I have not thought in detail about whether one could just defer certain parts of CxF as Not Yet Implemented, and still get the useful representational breadth and expandability of CxF color storage that set it apart from IES TM 27 14 ... but at first glance it seems plausible. Like one should be able to get utility out of an open-source CxF package even when incomplete.

I should probably start a separate issue for ... actually, I will.