[1.0.X] Fixed #7944: date-based generic views no longer get confused with a...

[1.0.X] Fixed #7944: date-based generic views no longer get confused with a numeric month format. Thanks to Justin Lilly and Alex Gaynor. Backport of r10457 and r10458 from trunk.

git-svn-id: http://code.djangoproject.com/svn/django/branches/releases/1.0.X@10459 bcc190cf-cafb-0310-a4f2-bffc1f526a37