Traceback in bzr difftools plugin when using external merge tool to compare two branches if branches contain symlinks

[Stephen Ward]

Hi,

I've modified bzr_difftools to use existing working trees in some cases where 
it previously resorted to temporary directories.  This fixes (or at least, 
avoids) the symlink bug that Elliot reported, and it has the added advantage 
that in-place edits will work in more cases than before.

The updated plugin is available at the usual locations.

-- Steve