Thanks ranjur for reporting bug, timgraham for review,
and collinanderson for contributing tips.

Thanks Tim Graham, Anssi Kääriäinen and Marc Tamlyn for the
reviews.

Refs #23426. Thanks Markus Holtermann for the suggestion.

Refs #23426

Fixed #23609 -- Fixed IntegrityError that prevented altering a NULL column into a NOT NULL one due to existing rows

Thanks to Simon Charette, Loic Bistuer and Tim Graham for the review.

This better reflects why I was invited to the team.

Added MEDIA_URL, FILE_UPLOAD_PERMISSIONS, and
FILE_UPLOAD_DIRECTORY_PERMISSIONS to the list of settings.

Thanks Petrus van Bork for the report.

This commit is a record that ed37f7e9 was my contribution.
Thanks Loic Bistuer for reviewing it.

Added update_or_create to RelatedManager, ManyRelatedManager and
GenericRelatedObjectManager.
Added missing get_or_create to GenericRelatedObjectManager.

Thanks Rolandde for the report.

Thanks edevil for the report and Simon Charette for review.

Fixed #22064 -- Add check for related_name

Fixed #23602 -- Add comment on get_absolute_url regarding user input

Thanks Troy Grosfield for the report and Tim Graham for the tests.

per Sphinx docs: "Using ref is advised over standard reStructuredText
links to sections because it works across files, when section headings
are changed, and for all builders that support cross-references.

Thanks Simon Charette for review.

Updated assertQuerysetEqual documentation following 311b3ad9