Converted sql_queries into a lazily evaluated list.

Fixed #23364. Thanks Markush2010 for the report.
Fixed a PEP 8 error.
Fixed #23055 -- Made generic admin filter obey ModelAdmin queryset.

Thanks to Trac user synasius and to Ola Sitarska for helping in
identifying the issue and helping with the test case.
Fixed #22820 -- Treated int and long types alike in lazy_number

Thanks kwist for the report and the initial patch.
Added a missing word in a skip message
Fixed #23388 -- Made django.utils.timezone.override usable as a decorator
Removed sentence from docs about migrate prompting to add a superuser.
Fixed #23391 -- Removed an erroneous backtip from the form's documentation.

Thanks to Trac alias nessita for the report.
Fixed #23371 -- Changed en_GB first day of the week to Monday.
Undocumented SeparateDatabaseAndState so crash is not RB. Refs #22918
Fixed ping_google management command to use argparse.
Fixed #22918 -- Fixed SeparateDatabaseAndState crash
Revert "Undocumented SeparateDatabaseAndState so crash is not RB. Refs #22918"

This reverts commit a8521a2c228bd9e981dc8a2bea4e26f4544a52a7.
Added missing import in docs/ref/signals.txt.
Initial commit.
More work.
Fixed spelling mistakes.
Converted checks to use built in checks framework.
Renamed some modules.
Split up tests.py