Fixed #20550 -- Added ability to preserve test db between runs
Implement Migration.run_before

This attribute (used for reverse dependencies) was previously declared
and mentioned in the code, but never actually used.
Revert "Making SQL management commands migration aware."

This reverts commit cb9c9a7b5879671053c7d2ad6e79943a8814b274.
Merge pull request #2726 from gchp/ticket-20550

Fixed #20550 -- Added ability to preserve test db between runs
Split GenericRelationsTests.test_generic_relations into several tests; refs #18586.
Fixed #21938 -- Moved documentation for error views to reference guide.
Fixed syntax error in ogrinspect.py management command.
Fixed #22659 -- Prevent model states from sharing field instances.

Thanks to Trac alias tbartelmess for the report and the test project.
Fixed #22711 -- Adjusted ordering checks to allow implicit relation fields.

refs #19195.
Fixed #22744 -- Fixed sqlite3 get_relations introspection with views

Thanks Tim Graham for the report and Simon Charette for the review.
Revert "Fixed #19303 -- Fixed ModelAdmin.formfield_overrides on fields with choices"

This reverts commit 9d1987d7679165ad3a7c2b713a8a488cc1421905.
Fixed #22690 -- Added a check for proxy models containing fields.

Removed the FieldError raised by ModelBase.__new__ in this case.
Fixed #22748 -- Corrected post_migrate usage example.

Thanks Rudolph for the report.
Fixed #11776 -- Added CSS class for non-field/top of form errors.

Thanks Daniel Pope for the suggestion.
Fixed #22753 -- Documented ability to use a note with the {% comment %} tag.
Unicode method on model should return unicode

The example of a __unicode__ model method should return a unicode value
instead of a string.
Fixed #22384 -- Deprecated reversing URLs by dotted path.
Merge pull request #2756 from tubaman/return_unicode

Unicode method on model should return unicode
Removed erroneous trailing comma in OLMapWidget.js.
Updated current state of MySQL Connector/Python.