[1.5.x] Updated link to jQuery Cookie plugin site

Backport of 81f454a322 from master
[1.5.x] Fixed #20492 - Removed a broken link in GIS docs.

Backport of fbab3209fc from master
[1.5.x] Rotate CSRF token on login

Backport of 1514f17aa60772f48839130f9a5071b9ffe15213 from master
[1.5.x] Fixed URL for six inventory.

Backport of 749c2e4 from master.
[1.5.X] Fixed #20513 - Expanded docs on QuerySet caching.

Thanks seddonym.

Backport of 8365d76da0 from master
[1.5.X] Fixed #20523 - Incorrect form field for FilePathField.

Thanks sane4ka.sh@ for the report.

Backport of 1fdc3d256d from master
[1.5.x] Fixed #20525 -- Added versionadded for clearsessions.

Thanks wiml@.

Backport of 8a6e040bfa from master
[1.5.x] Fixed regroup example.

Chicago was missing.

Backport of e6ff238 from master.
[1.5.x] Fixed #20326 - Corrected form wizard get_form() example.

Thanks tris@ for the report.

Backport of 646a2216e9 from master
[1.5.x] Fixed #20166 - Corrected TEST_DEPENDENCIES example in testing docs.

Thanks czambran.

Backport of f10e9af227 from master
[1.5.x] Fixed #20543 - Typo in db model fields docs.

Thanks i.amber.jain@ for the report.

Backport of f315693304 from master
[1.5.x] Fixed #20545 - Made class-based view MRO lists consistent.

Thanks wim@ for the suggestion.

Backport of c36b75c814 from master