gnome_upgrade.sh for Gnome-2.6 and Gringotts

[supraexpress at globaleyes.net]

Since Gringotts wants "gtk-x11-2.0.200" and borks on "gtk-x11-2.0.400", it
might be good to include this in the 'List of Gnome2.6 problems and their
solutions', as this causes the upgrade process to fail.

Of course, once Gringotts is fixed to work properly with
"gtk-x11-2.0.400", then this should no longer be an issue. Until such
time, it should be included in the EXCLUDE_PORTS (environment variable)
list.