Made a doctest compatible with Python 2

That test might not always execute, but can be executed when the
parent test label is explicitely given.
Fixed versionchanged indentation in unit-tests.txt.
Fixed #23630 -- Made AlterModelTable rename auto-created M2M tables.

Thanks Naddiseo for the report, Andrew Godwin for guidance,
and Shai Berger for review.
Fixed #23705 -- Removed unnecessary AliasMatch from example Apache config.

Thanks Keryn Knight for the report.
Added missing available app in migrations test case

In some test combinations, having contrib.auth available but not
contrib.contenttypes can produce failures while creating permissions.
Fixed #23444 -- Deprecated django.contrib.admin.helpers.InlineAdminForm.original_content_type_id
Fixed #23702 -- Fixed adding an explicit id field on SQLite.

Thanks gavinwahl for the report.
Fixed #23707 -- Prevented discovery of duplicated tests
Fixed typo in docs/ref/request-response.txt
Fixed #23618 -- Allowed apps with no models to still have migrations

Basically a4737bf6ae reapplied.
Updated gis_migrations tests
Fixed #23652 -- Restored database name after destroying test database

Thanks Bjarkias for the report.
Removed unused import
Fixed versionchanged indentation in topics/testing/advanced.txt.
Replaced dead links to python-distribute.org.
Removed simplejson inventory file from docs/conf.py.
Fixed #23446 -- Officially recommended mysqlclient as MySQL driver

Thanks Corey Farwell for the report and Tim Graham for the review.
Thanks also to Inada Naoki for creating and maintaining mysqlclient.
Fixed documentation of make_password kwargs.
Fixed #23699 -- Prevented flush from loading initial data for apps with migrations.
Forwardported release note for refs #23621.