add obsolete parents wrapper to the 'parents' command
although the command itself cannot *cause* obsolete changesets, the
information is rather relevant to the state of the parents
This software was downloaded from
https://bitbucket.org/marmoute/mutable-history
Copyright 2011 Peter Arrenbrecht <peter.arrenbrecht@gmail.com>
Logilab SA <contact@logilab.fr>
Pierre-Yves David <pierre-yves.david@ens-lyon.org>
Patrick Mezard <patrick@mezard.eu>
This software may be used and distributed according to the terms of the GNU
General Public License version 2 or any later version.
On Debian systems, the complete text of the GNU General Public License version
2 can be found in `/usr/share/common-licenses/GPL-2'.