[PATCH] export to tar file

[Lalo Martins]

This patch introduces "plugins" to export a revision.  Normal export
behaviour is unchanged, but it's now called "the 'dir' exporter".  Added
are a 'tar' exporter, and building on it, a 'tgz' and a 'tbz2'
exporters.  The 'zip' exporter is left as an exercise to the reader,
since I don't use zip files much :-)

DISCLAIMER
the legal status of this patch is questionable... as I created some new
files, and I didn't know whether I should begin them with
# Copyright (C) 2005 Canonical Ltd
or
# Copyright (C) 2005 Lalo Martins
so I went with the former.  This is of course easy to solve once someone
figures out the right thing to do.


best,
                                               Lalo Martins
--
      My personal formula for efficiency is to arrange
     problems in such a way that they solve each other.
--
http://www.exoweb.net/                  mailto:lalo at exoweb.net
GNU: never give up freedom                 http://www.gnu.org/