Fixed #21774 -- Isolate all test urls from eachother.

This (nearly) completes the work to isolate all the test modules from
each other. This is now more important as importing models from another
module will case PendingDeprecationWarnings if those modules are not in
INSTALLED_APPS. The only remaining obvious dependencies are:

- d.c.auth depends on d.c.admin (because of the is_admin flag to some
  views), but this is not so important and d.c.admin is in
  always_installed_apps
- test_client_regress depends on test_client. Eventually these should
  become a single module, as the split serves no useful purpose.

django/contrib/auth/tests/test_templates.py

@@ -17,6 +17,7 @@ from django.utils.http import urlsafe_base64_encode
     PASSWORD_HASHERS=('django.contrib.auth.hashers.SHA1PasswordHasher',),
 )
 class AuthTemplateTests(TestCase):
+    urls = 'django.contrib.auth.tests.urls'
 
     def test_titles(self):
         rf = RequestFactory()

django/contrib/auth/tests/urls.py

@@ -1,4 +1,5 @@
-from django.conf.urls import patterns, url
+from django.conf.urls import patterns, url, include
+from django.contrib import admin
 from django.contrib.auth import context_processors
 from django.contrib.auth.forms import AuthenticationForm
 from django.contrib.auth.urls import urlpatterns
@@ -98,4 +99,7 @@ urlpatterns = urlpatterns + patterns('',
     (r'^auth_processor_messages/$', auth_processor_messages),
     (r'^custom_request_auth_login/$', custom_request_auth_login),
     url(r'^userpage/(.+)/$', userpage, name="userpage"),
+
+    # This line is only required to render the password reset with is_admin=True
+    (r'^admin/', include(admin.site.urls)),
 )