gnome-color-manager now requires lcms2

[Richard Hughes <hughsient gmail com>]

I've just switched gnome-color-manager in git master to require lcms2.
The author of lcms has switched development efforts to lcms2, and now
lcms1 won't get any new features or anything other than security bug
fixes. lcms2 is however parallel installable with lcms, so that makes
it easier on projects that already depend on lcms to migrate at a good
point.

lcms2 is quite a lot faster in my benchmarks, and does allow us to do
some cool things, namely manual calibration without a specrophotometer
(like OSX). Expect funky screenshots in the near future.

I hope this is okay, and should also give the few remaining distros
(cough, debian, cough) a push to finally package lcms2.

Richard.