goffice font selector

[Robert Staudinger <robert staudinger gmail com>]

Hi, 

i'm working on a new font selector for abiword ATM. Jody pointed me to
the one that's already in goffice-gtk, so i looked at it. This one
seems to be somewhat out of sync with gtk's own (extra entries for
font and variant, spacings).

Since i'm pretty far already now that i learnd about the goffice
filesel i'm wondering if you would accept to completely replace the
goffice filesel with another implementation based on gtk's. The
changes are minimal, i removed the deprecated stuff, added an
extension area (like GtkFileChooser) and made it auto-apply (close
button only). I also wrapped all the changed to the fontsel-widget in
the fontsel-dialog, so it should be convenient to use.

Best, 
- Rob