[1.7.x] Fixed #23114 -- Clarified documentation of template lookups.

Thanks to gmunumel and Tom Dalton for their help on the patch.

Backport of 62c74abbb06a081708c2cb5cc459f39beb26acaa from master.
[1.7.x] Fixed #23123 -- Don't use a bare except in ModelAdmin documentation

Thanks to wkschwartz for the report and to Tim for the patch.

Backport of e5619330e2d3bf901155e98ef3fa7d224b6a260a from master.
[1.7.x] Fixed #23120 -- Updated GeoDjango tutorial for migrations workflow.

Backport of b012122d30 from master
[1.7.x] Fixed #23079 -- Added data loss issues to those that will be backported to LTS.

Backport of e46801f13d from master
[1.7.x] Forwardported 1.6.6 release notes for refs #20292.

Backport of f294f93a17 from master
[1.7.x] Make detect_soft_applied exit correctly on non-create migrations
[1.7.x] Fix soft_applied in a way that doesn't break tests
[1.7.x] Fixed a typo in the admin documentation.

The 'app' subpackage does not exist, should be 'app'.

Backport of b9daa4f0e1 from master
[1.7.x] Fixed #23101: Prefer doing deletes before creates in autodetector.

Makes declined or missed renames still work (but drop data).
[1.7.x] Fixed #23090: Document and enforce not double-squashing migrations
[1.7.x] Fixed #23127: south_migrations note in docs
[1.7.x] Fixed #23092: Squashing handles external dependencies