Fixed #23097 -- Switched to new octal format in docs
Added test for the #23070 problem
Fixed code to solve #23070 problem

Added a class to wrap callable in settings:
* Not to call in the debug page (#21345).
* Not to break the debug page if the callable forbidding to set attributes (#23070).

Thanks @bmispelon for giving me some advice.
Fixed #22887 -- Added comment for translators on unique_for_date error message
Merge pull request #2967 from hirokiky/fix23070

Fixed #23070 -- not to break the debug page by callable setting with __slots__
Fixed #22305 -- Added note to docs about UTF8 database requirement.
Fixed #23103 -- Added contributing tutorial link to contributing index.
Fixed #16617 -- Added 'value' to BaseValidator params.

Also allowed overriding the default messages in subclasses of BaseValidator.

Thanks sperrygrove for initial patch.
Fixed #22553 -- Added refreshing queryset info to docs.
Fixed #22873 -- Renamed use_debug_cursor to force_debug_cursor to clarify the behavior.
Fixed #23060 -- Prevented UnicodeDecodeError in debug templatetag
Fixed #22944: Bad dependency on FK alteration in autodetector
Fixed #23101 db_table wasn't copied in deconstruct

Forward port of 999758fc7a2d6fcb01eb40de937d4420f884788d from
stable/1.7.x
Fixed #23106 -- Updated class-based view reference title.
Fixed #22979 -- Moved bug* tests
Only warn about initial data if fixtures have been found.
Fixed #23098 -- Checked that lazy choices are not evaluated too soon

Thanks Matthieu Agopian for the report.
Update from key ID in security.txt to authorized release keys list.
Correctly remove extraneous text about keys from previous edit.
Fixed #23062 -- Documented how to create superuser.

Patch by Tim Graham. Thanks areski for the review.