Report from running bzr diff with difftools and tkdiff

[Stephen Ward]

Hi John,

I have a couple of questions about the 2nd, more complete patch for the 
interactions between the bzr_difftools plugin and lazy_import.

1. why get rid of the "from bzrlib.errors import BzrError" from one file 
(externtool.py), but leave it in another (__init__.py)?

2. why didn't you also get rid of remaining function imports in __init__.py,
such as:

  from bzrlib.commands import register_command
  from bzrlib.transport import get_transport

  Wouldn't these also pose some risk as lazy_import is more widely used?  Or
  are these in areas that aren't likely to ever be lazy_imported?

These aren't criticisms; I'm happy that you took the time to make these 
changes.  I just want to make sure I understand them, and particularly I want 
to make sure that we've fixed the problem completely.

Thanks,

Steve