Hi,

Please find attached an updated patch.

Summary of changes:

1. Most of feedback from Nick Coghlan and Serhiy Storchaka is applied;

2. Changes in difflib.py were reverted (unless we add the __future__ import there right now there is no need to fix it);

3. Chris' test is integrated to the patch.

All in all I think it's in a good shape now, but I'd appreciate if someone looks at genobject.c changes one more time.