Doc cleanup for FormMixin.prefix; refs #18872.
Fixed #19773 - Added admin/popup_response.html template.

Thanks jimmylam@ for the suggestion.
Fixed #20642 -- Deprecated `Option.get_(add|change|delete)_permission`.

Those methods were only used by `contrib.admin` internally and exclusively
related to `contrib.auth`. Since they were undocumented but used
in the wild the raised deprecation warning point to an also undocumented
alternative that lives in `contrib.auth`.

Also did some PEP8 and other cleanups in the affected modules.
Fixed #20650 -- Fixed {% filter %} incorrectly accepting 'escape' as argument

Thanks to grzesiof for the report and to loic84 and Alex Gaynor
for the review.
Fixed missing initializations in WSGIRequest. Refs #20619
Fixed #20658 -- Fixed bad reST formatting and missing parentheses in the docs for CBV mixins

Thanks to Keryn Knight for the report.
Fixed #20462 -- null/non-string regex lookups are now consistent

Thanks to noirbizarre for the report and initial patch.
Fixed #20462 - Replaced the str() cast introduced in 273dc55 by force_text()
Merge pull request #1308 from loic/ticket20462

Fixed #20462 - Replaced the str() cast introduced in 273dc55 by force_text()
Fixed #14881 -- Modified password reset to work with a non-integer UserModel.pk.

uid is now base64 encoded in password reset URLs/views. A backwards compatible
password_reset_confirm view/URL will allow password reset links generated before
this change to continue to work. This view will be removed in Django 1.7.

Thanks jonash for the initial patch and claudep for the review.
Add missing preposition in documentation
Merge pull request #1309 from treyhunner/patch-1

Add missing preposition in documentation.
Fixed #20665 -- Missing backslash in sitemaps documentation

Thanks to roman for the report.
Fixed #20541 -- don't raise db signals twice when creating superuser
Fixed #20590: Documented new test case ordering
Add related_query_name to ForeignKey/M2M. Refs #20244
Fixed LOGGING setting docs
Merge pull request #1311 from loic/ticket20619_take2

Fixed missing initializations in WSGIRequest. Refs #20619
Docs for related_query_name
Fixed #20244: PermissionsMixin now defines a related_query_name for M2Ms