stack: get stack data directly from stack and remove stackdata()
stackdata function began its life in 137f8b04901e as a proto-stack: it computed
stack revs on its own and only had one property to return, "changesetcount".
Later it started to prepare and return more properties, but since b933a8068c17
it was computing revs using a getstack function. And then finally in
17749d9d3968 it started to rely on stack class entirely.
It was a good function, but now, when all the logic it provided was factored
into stack class, I'd say it's finally time for it to be put to rest.
This software was downloaded from
https://www.mercurial-scm.org/repo/evolve/
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'.