[1.6.x] fixed grammar

  ``{{ obj.view_href }}`` will cause template rendering to fail if

  ``view_href()`` raises ``NoReverseMatch``. There is no change to the

  ``{% url %}`` tag, it causes template rendering to fail like always when

  ``NoReverseMatch`` is risen.

  ``NoReverseMatch`` is raised.

* :meth:`django.test.client.Client.logout` now calls

  :meth:`django.contrib.auth.logout` which will send the