Fixed #19802 -- Fixed HttpResponse.set_cookie() with unicode data on Python 2.

Thanks django at patrickbregman.eu for the report.
Fixed flake8 warning.
Revert "Fixed #23088 -- Used `six` `range` type in `Paginator.page_range`."

This reverts commit 6508db2ff9fc5be95fec903b3fa7ab8204fe316a.

Refs #23088.
Ensured that Paginator.page_range works the same on Python 2 and 3.

This somewhat fixes #23088, refs 23140.
Fixed #23160 -- Correctly rename models with self referential fields.

Thanks to whitews AT gmail for the report.
Fixed a MySQL test failure introduced by cbb29af1aa.

Seems like unlike other backends MySQL get_constraints fails when dealing
with a non-existing table. refs #23160.
Fixed #23091: CreateModel and AddField were clashing with deferred SQL
Fixed #23153: Properly recreate spatialite triggers on alter table
Fixed #23163: Align user help text with migrations
Fixed #23161: Drop PostGIS geography fields correctly
Corrected a comment in forms/forms.py; refs #16612.
Fixed #22745 -- Prevented reevaluation of ModelChoiceField's queryset when accesssing BoundField's attrs.

Thanks Christian Schmitt for review.
Fixed #23169 - Misc docs fixes.
Fixed #22234 -- Replaced OS-specific code with subprocess.call() in dbshell.

This fixes escaping of special characters on Windows.
Fixed #16311 -- Added a RelatedOnlyFieldListFilter class in admin.filters.
Fixed two tests in previous commit; refs #16311.
Fixed a typo in comment in django/utils/version.py
Fixed test failures from 98e8da3709e400d549e87c7ff1450a2685c0adcf.
Fixed #23061: Avoided setting a limit on a query for get with select_for_update on Oracle

Thanks Michael Miller for reporting the issue.
Stop errors on older Spatialite versions that miss some tables