This reverts commit c82be665.

This reverts commit 3bae1a9a.

Retrospectively, there is no reasonto wrap every request in a
transaction of its own. Developer should actively consider isolation
in their code.

This came up while trying to figure out how to delay every Celery task
until commit, finding us monkey-patching amqp, and failing.

Merge branch '359-make-celery-non-optional' of edugit.org:AlekSIS/Official/AlekSIS-Core into 359-make-celery-non-optional

Merge branch '359-make-celery-non-optional' of edugit.org:AlekSIS/official/AlekSIS-Core into 359-make-celery-non-optional

Refactor ProgressRecorder for non-optional Celery usage and add doc strings

See merge request !494

Rewrite dirtyfields with FieldTracker

See merge request !492

Release 2.0a4

See merge request !488

Resolve "[About] Shows versions as "unknown""

Closes #365

See merge request !487

Add django-extensions

See merge request !486

What did I drink when I wrote the original code? The relative import
`from .. import __version__` in the utility code in core, of course,
always imported from `aleksis.core`, no matter the real `AppConfig`
that inherited the utility code. Thus, the versions always showed the
version of AlekSIS-Core everywhere (whose version information was
broken ever since we renamed AlekSIS to AlekSIS-Core).

This change decouples the `get_version` code from the package level
`__version__` information, which effectively becomes optional now.

Rewrite logic for AlekSIS/Django user/group sync to only save if necessary

Closes #350

See merge request !485