prune: have dirstate collaborate with transaction
With 3.6, dirstate update can work with transaction to ensure proper rollback.
We do it if the mercurial version permit it.
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'.