Fixes reftests that were broken after images and labels applied padding.
Things look much more cramped now. On the plus side, treeview headers
and comboboxes have better spacing. Menubars look like crap now though.
Needs someone with artistical talent to figure out.
Just set oit for things that need it.
(FIXME: Buttons should probably not need it, but spinbuttons and
treeview headers don't have a proper background without it.)