Show link to /site/user/list on /site/user/lookup when User is not found.
http://code.google.com/p/soc/issues/detail?id=61
Patch by: Chen Lunpeng
Review by: Todd Larsen (with modifications)
# coding: utf-8
r"""
>>> from django.contrib.comments.models import Comment
>>> from django.contrib.auth.models import User
>>> u = User.objects.create_user('commenttestuser', 'commenttest@example.com', 'testpw')
>>> c = Comment(user=u, comment=u'\xe2')
>>> c
<Comment: commenttestuser: â...>
>>> print c
commenttestuser: â...
"""