Patch #16774 -- Views can raise DoesNotResolve to make the URL resolver continue resolving.

This pull request allows views to raise urlresolvers.DoesNotResolve to make the URL resolver to ignore the view and keep resolving the URL. 

https://code.djangoproject.com/ticket/16774
https://groups.google.com/forum/#!topic/django-developers/BAk5pGb7zE8/discussion