Fixed #21912 -- Improved error message if a view returns None.

Thanks brycenesbitt for the report.
Fixed some flake8 errors from recent commits.
Fixed #22047 -- detecting related_name clash with inheritance

Thanks to mondone for fruitful colaboration.
Improved fix for #18373 -- backward compatibility

Commit 79558c78 cleaned up the (undocumented) interface of Resolver404
exception, which breaks compatibility with code messing with .args[0]
directly. Revert the cleanup part and simply leave the fix itself.
Fixed #22013 -- Documented difference between SERVER_EMAIL and DEFAULT_FROM_EMAIL.
Fixed #21725 -- Fixed JavaScript quoting encoding.

Thanks to nedbatchelder for the report.
Corrected a pair of flake8 violations
Fixed #22002 -- Documented avoiding database interaction in AppConfig.ready().

Thanks Marc Tamlyn for the suggestion.
Split line and added indentation for better readability.
Fixed bad comparison logic introduced in d97bf2e9c8971764690caaf81a0914bc368d6b02.

Refs #21765.

Thanks to kezabelle for the quick report and to onjin
for providing the patch.
Fixed #18745 - Documentation change explaining tuple to list with signing.

Thanks to lee for the report.
Fixed #21939 -- Deprecated loading ssi/url tags from future.
Fixed two typos in documentation
Added some links in i18n documentation
Made the new template.Context.flatten() method a public API.

That method was introduced in 9db4271bd11ac23a5a5652bbcdf8fb6d4b997651.

Refs #21765.
Fixed #19980: Signer broken for binary keys (with non-ASCII chars).

With this pull request, request #878 should considered closed.

Thanks to nvie for the patch.
Merge pull request #2270 from bmispelon/ticket-22030

Fixed #22030 -- Don't assume that all fields have a swappable_setting at...
Added the possibility to pass a stdin object to a management command.

This makes testing certain features easier.

Thanks to AeroNotix for the original patch.
Use assertEqual instead of assertEquals.
Fixed #7423 -- Skip superuser creation when not running in a TTY.

Thanks to trac user galaxy4sale for the original report
and to AeroNotix for the patch.