Groups in cgit

[Shaun McCance <shaunm gnome org>]

Owen and I discussed doing repository groups in cgit using
the category property in each module's doap file.  Attached
is a patch to make this happen on the server.

Categories in doap are resources, which means they're given
using URLs.  To have a simple controlled vocabulary, this
uses resources defined in our doap-extensionsd file.

If we do this we should:

1) Update doap-extensiosn on api.gnome.org.  Attached.
(Aside: Should we have a git repo for the contents of
api.gnome.org?)

2) Have Pulse put the category in the template files.  It
should be reasonably reliable for our "core" modules.

--
Shaun