Added the CSRF_TRUSTED_ORIGINS setting which contains a list of other
domains that are included during the CSRF Referer header verification
for secure (HTTPS) requests.

Thanks Anssi Kääriäinen for providing the solution.

The corresponding HTML was removed in
738d9af1.

Thanks Marcin Biernat for the initial patch and tests.

Fixed #25058 -- Added GenericRelations with related_query_name to the admin's delete confirmation page.

Thanks Tom Christie for the report and review.

This is preparation for landing the template-based widget rendering
patch and goes a long way to making these tests more useful for future
development. The old doctest heritage is strong here.

Was added in 44164c5c but the
transaction.commit_unless_managed() line was removed in
ba5138b1; thus the test does nothing
but check that clear() runs.

Using select_related() after .values() or .values_list() is not possible
because .values() or .values_list() already got the values they need.