Fix broken test
Fix __latest__ to actually resolve to the latest migration
Fixed #22861: Internal migrations done first so __first__ works

Thanks to Chris Beaven.
Fixed several flake8 errors
Fixed #14481 -- Documented implicit "through" class created by ManyToManyField.

Thanks to jonathanmorgan for the report and initial patch.
Fixed #22778 -- Added a model Meta option to define default_related_name.

Thanks jorgecarleitao and mmardini for reviews.
Fixed #22859 -- Improved crossDomain technique in CSRF example.

Thanks flisky for the report.
Removed a CSRF example for jQuery < 1.5.