[1.7.x] Limited lines to 119 characters in django/{contrib,db}.

Refs #23395.

Backport of c9178ef17a (to decrease chance of backport conflicts) from master
[1.7.x] Fixed #23719 -- Fixed MySQL 5.6 crash with GeometryFields in migrations.

Backport of 03bd79ed2 from master
[1.7.x] Fixed #23614 -- Changed the way the migration autodetector orders unique/index_together

Thanks to Naddiseo for the report and Tim Graham for the review

Backport of 5c9c1e029d from master
[1.7.x] Added cross reference in admin docs to topic about saving objects in formsets.

Backport of 388c6038fd from master