Adding device profiles

[Richard Hughes <hughsient gmail com>]

In GCM, you can currently add "virtual" devices which you manually
populate the fields then assign a profile. This sucks monkey balls.

What I really want is to be able to point GCM at a RAW file (or TIFF,
or PNG, or JPG) and for it to read out the metadata (EXIF data) and
populate those text fields for me, and then autoselecting a profile if
you've got one that matches. This allows us to provide the feature on
the DBus interface too.

To do this, I either need to depend on exiftool (perl, ick) or
exifinfo (python, ick) or I can just decode the headers myself like
I'm already doing for TIFF files.

Assuming I do the latter, I really need a raw decoder, and the only
one that looks sane from a packaging point of view is libopenraw --
which looks pretty easy to use. I can always make this a conditional
build-time dep if this is not available in all distros.

So, comments? Better ideas?

Richard.