Another regression fix for select_related handling

This time gis compiler.get_default_columns() wasn't up to date. Thanks
to CI another regression fixed.

Refs #13781
Update django/contrib/flatpages/forms.py

Translate before passing in the variables (i.e. close the bracket earlier).
If you translate after passing in the variables the translated value will contain the actual values for 'url' and 'site' and will therefore not be translated.

(I'm not actually using django's flatpages, but I ran into this apparent error when doing a global grep on my own project)
Fixed #19296 -- Applied test connection sharing for spatialite

Thanks pegler at gmail.com for the report and the initial patch.
comment_will_be_sent can cause a 400, not a 403

Doc cleanup for django.contrib.comments.signals.comment_will_be_sent
If a receiver returns False, an HttpResponse with status code 400
is returned. A test case already exists confirming this behavior.
Updated docs to reflect reality.
Merge pull request #521 from emidln/master

Fixed docs noting comment_will_be_sent signals return 400 status code
Fixed #18985 -- made DeprecationWarnings loud

Capture warnings in Python >= 2.7 and route through
console handler, which is subject to DEBUG==True

Thanks to dstufft for the idea, and claudep for initial patch
Documented that contrib.sites creates a default site.

Thanks Lorin Hochstein for the patch.
Fixed #19136 -- Properly escape gettext context prefixes in the i18n JavaScript view template.
Merge branch 'master' of github.com:django/django
Merge pull request #490 from gabrielhurley/reverse-prefix-special-chars

Fixed #18210 -- Escaped special characters in reverse prefixes.
Fixed typo introduced in 4a5e8087ac7676ef08e76275c1f756778b39c13e.
Fixed #19310 -- changed method docs formatting for custom file storage docs
Fixed #18989 -- Removed unused condition in CursorWrapper

Thanks zimnyx for the report.
Fixed #19226 -- Applied linebreaksbr to read-only fields in admin

Thanks shadow for the report, and Melevir and thiderman for the
patch.
Refactor loaddata for readability.

Thanks Claude Paroz and Daniel Moisset for review and feedback.
Fixed #19036 -- Fixed base64 uploads decoding

Thanks anthony at adsorbtion.org for the report, and johannesl for
bringing the patch up-to-date.
Fixed #19114 -- Fixed LogEntry unicode representation

Thanks niko at neagee.net for the report and Emil Stenstrom for
the patch.
Fixed #16779 - Added a contributing tutorial

Thank-you Taavi Taijala for the draft patch!
Fixed #2550 -- Allow the auth backends to raise the PermissionDenied exception to completely stop the authentication chain. Many thanks to namn, danielr, Dan Julius, Łukasz Rekucki, Aashu Dwivedi and umbrae for working this over the years.
Merge pull request #466 from kenthauser/ticket_19025

#19025 Add `form` to formwizard context (includes tests)