[MERGE] Shelf supports multiple diff writers.

[Aaron Bentley]

-----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA1

Robert Collins wrote:
> bb:approve; looks fine to me.
> 
> I wonder perhaps if the registry should be in e.g. diff.py rather than
> option.py?

My theory is that we should minimize the number of things that plugins
must import every time.  option.py is something that is required on
every bzr run, so importing it carries no cost.  But diff.py or shelf_ui
(which is where I thought was the most natural place for it) would be
more expensive to import.  I've been thinking we should probably
centralize all our registries, but this is somewhere to start.

Aaron
-----BEGIN PGP SIGNATURE-----
Version: GnuPG v1.4.9 (GNU/Linux)
Comment: Using GnuPG with Mozilla - http://enigmail.mozdev.org

iEYEARECAAYFAkkg4EkACgkQ0F+nu1YWqI2VTACfbdrsO2S+BOPf9bClucebO35p
FtAAn0+C4FPoeYnwBXDvfKj1692k+Tmm
=08xQ
-----END PGP SIGNATURE-----