[1.7.x] Fixed #23785 -- Typo in docs/releases/1.6.txt

Backport of 091f5b5a4e from master
[1.7.x] Fixed a typo in 1.6 release notes.

Backport of 006451f894 from master
[1.7.x] Fix a typo in 1.7 release notes

Backport of faf4d5c510 from master
[1.7.x] Fixed #23774 -- Clarified QuerySet.order_by() and related models.

Backport of 11b7680d0e from master
[1.7.x] Fixed #23795 -- Fixed a regression in custom form fields

Custom form fields having a `queryset` attribute but no
`limit_choices_to` could no longer be used in ModelForms.

Refs #2445.

Thanks to artscoop for the report.

Backport of bfb11b95626f39e2f5e18d97d7761c6f93dcc1a9 from master.

Conflicts:
	django/forms/fields.py
Mysql db check should handle None db_type returns. Backport from https://github.com/django/django/commit/e9103402c0fa873aea58a6a11dba510cd308cb84#diff-14
Release note for db_type mysql fix
Add regression tests for ticket 23761