This new technique is more straightforward and compatible with test
parallelization, where the effective database connection settings no
longer match settings.DATABASES.
Made it possible to register and run callbacks after a database
transaction is committed with the `transaction.on_commit()` function.
This patch is heavily based on Carl Meyers django-transaction-hooks
<https://django-transaction-hooks.readthedocs.org/>. Thanks to
Aymeric Augustin, Carl Meyer, and Tim Graham for review and feedback.
The primary use case is to interact with a third-party database (not
primarily managed by Django) that doesn't support time zones and where
datetimes are stored in local time when USE_TZ is True.
Configuring a PostgreSQL database with the TIME_ZONE option while USE_TZ
is False used to result in silent data corruption. Now this is an error.
Mark Young
Tim Graham
Chris Jerdonek
Simon Charette
Barthelemy Dagenais
Adam Chainz
Aymeric Augustin
Andreas Pelme
Collin Anderson