colord: Support CCSS data files

Add a CdSpectrum object to libcolord for easy manipulation of spectral data.
Add a cd-csv2cmf binary that allows us to generate some data files
colord: Add a utility function to calculate an XYZ value from a CMF
Install the CIE 1931 2deg and CIE 1964 10deg CMF data files

The original source of these data files is http://www.cvrl.org/cmfs.htm
which was then processed with cd-csv2cmf.