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)
This is an optional add-on app, flatpages.
For full documentation, see either of these:
* The file docs/flatpages.txt in the Django distribution
* http://www.djangoproject.com/documentation/flatpages/ on the Web
Both have identical content.