Refs #24015.

Thanks Tim Graham for the report and initial patch.

Thanks Tim Graham for the review.

This prevents AppRegistryNotReady errors when unpickling Django
models from an external script.

It may not be installed on all systems.

Thanks Brian Jacobel for the report. refs django/djangoproject.com#197

Previously Publisher.objects.filter(book=val) would target
book.object_id if book is a GenericRelation. This is inconsistent to
filtering over reverse foreign key relations, where the target is the
related model's primary key.

Thanks kmmbvnr for the report.

Fixed #23893: Added tzinfo to constant datetime in unit test

Added tzinfo to y2k constant (01/01/2000) in
custom_lookups.tests.DateTimeLookupTests.test_datetime_output_field
to fix warning message regarding naive datetimes.

Copied technique from schema tests.

Thanks to Tim Graham for reporting the issue; refs #23822

A default is no longer required.

Specify an id to avoid conflict with objects created in setUpTestData.

This keeps tests/__init__.py from importing other modules and may fix a problem
with test discovery revealed in formtools tests on Travis CI.

Thanks to Shai Berger, Loïc Bistuer, Simon Charette, Andrew Godwin,
Tim Graham, Carl Meyer, and others for their review and input.

This commit prepares the internal manager layout to be serialized by
migrations; refs #23822.

Thanks Josh Smeaton for review.

Fixed #23992 -- Optimized reorder_suite functions using OrderedSet

Refs #23989.
Forward port of eb632bfb from stable/1.7.x.

Running this file as a standalone script doesn't work anyway.

(this includes a forward-port of 9189ef43)