Fixed #21281 -- Made override_settings act at class level when used as a TestCase decorator.
Fixed spelling mistake in docs/ref/request-response.txt
Fixed #23300 -- Made assertTemplateUsed throw an error on responses not fetched using the test client.

Thanks zags for the report and bmispelon for the patch.
Changed docstrings in admindocs/utils to comply to PEP 257
Fixed #5405 -- Added admindocs support for reStructured text in model docstrings

Thanks elvard and gkmngrgn for work on the patch and Markus H. for review.
Fixed typos using https://github.com/vlajos/misspell_fixer
Fixed versionchanged indentation in docs/.
Added HStoreField.

Thanks to `django-hstore` for inspiration in some areas, and many people
for reviews.
Added a warning about nonexistent FK constraints when unmigrated apps depend on migrated ones.

Thanks NotSqrt for the report; refs #23741.
Fixed links to mysqlclient in database notes.
Fixed #13181 -- Added support for callable choices to forms.ChoiceField

Thanks vanschelven and expleo for the initial patch.
Removed unused import.
Added missing docs to DiscoverRunner for keepdb option; refs #20550.
Fix minor typo in documentation.
Fixed #23531 -- Added CommonMiddleware.response_redirect_class.
Updated six to 1.8.0.
Removed confusing paragraph from the docs.

This snippet wasn't particularly helpful as `add_error()` is described
in greater details in the following section.

Thanks Claude Paroz for the report.
Added "Features removed in 1.8" section to release notes.
Removed redundant link in 1.7 release notes.
Added a dummy class for HTMLParserError; refs #23763.