Adding printer profiling support

[Richard Hughes <hughsient gmail com>]

In a few days time, my nice lovely ColorMunki should be delivered.
Before it is, I figured I should get up to speed on how to profile
printers, so we know what UI to add to GCM, and so I can get up to
speed quickly.

So. Does anybody have any hints, tips or suggestions on how to
calibrate a printer. Device specific options (e.g. "The ColorMunki
works really well with -f234 -g567") are more than welcome, as we
already know the colorimeter device type.

In particular, we need to support printing to 6x4 inch cards, A4 and
letter paper. I would love to integrate this better with CUPS (using
the GTK print dialog for instance) than what we can do on the command
line. We'll also need scans of the patches sheets that we send out, so
we can show the user _how_ to scan in the patches. We'll also probably
need a timer for "waiting for the ink to dry" and that sort of thing.

Ideas very welcome.

Thanks,

Richard.