Awhile ago, I've been wondering if anybody would be interested in bumping
gtk version requirement for gconfig, in order to drop libglade
dependency.

That, in turn, would make it possible for building it against gtk 3,
with a few tweaks.

Attached patch is more of an idea, than anything complete. AFAICT, it
seems to be working correctly (for the most part) with gtk 2 and is also
partially working with gtk3.

There's quite a bit of cruft there, as I still haven't figured out how
to correctly initialize the initial interface choice
(full/split/single).

Also, with gtk 3, something isn't working correctly in single/full
(split seems fine) and there are odd gtk warnings upon closing - I'll
need to look into that.

gconf.glade is attached as a new file, as it's a gtkbuilder file now.
IIRC, GDK_<> -> GDK_KEY_<> would require at least gtk 2.22, but that
could be dealt with a couple #ifdef, other than that, at most 2.14 would
be needed.

So, if there's any interest, comments are welcome.