Fixed test failure on python 3.x.
Fixed #22971 -- Properly parsed RFC 2388 encoded headers

Thanks homm for the report, Cea Stapleton for patch improvements
and Ian Cordasco, Christian Schmitt and Tim Graham for the review.
Fixed #23265 -- Used system-specific encoding in runserver

Thanks SpaceFox for the report.
Fixed #21132 -- Removed the useless app_name argument to AdminSite.

Thanks MarkusH for the report and Florian for review.
Fixed #21579 -- Made LocaleMiddleware respect script prefix.

Thanks buettgenbach at datacollect.com for the report and patch.
Fixed #23260: Added generator support to defaultfilters.unordered_list.
Fixed #23291 -- Don't add Unicode varname/value to environment.

Windows doesn't like that and it causes 114 failures in the
admin_scripts tests with Python 2.x.
Fixed a grammar error in docs/ref/forms/api.txt.
Fixed #23224 - Documented EmailValidator.
Fixed #20133 -- Added summary to admin deletion confirmation pages.

Thanks jonash for the suggestion and initial patch.
Added some words to spelling_wordlist.
Fixed #23288: deconstruct() ignoring related_name
Complemented 1.6 release notes for 457c16d0d6

And accessorily added missing bits fixing #23293.
Forward port of 2cbafd814 from stable/1.7.x
Fixed typo in docs/howto/custom-model-fields.txt.
Fixed #23162 -- Renamed forms.Field._has_changed() to has_changed().
Fixed #23269 -- Deprecated django.utils.remove_tags() and removetags filter.

Also the unused, undocumented django.utils.html.strip_entities() function.
Fixed #23287 -- Updated error message for classonlymethod decorator.
Fixed typo in tests/migrations/test_operations.py
Fixed #18355 -- Added ordering options to list based generic views.

Added MultipleObjectMixin.ordering and get_ordering().

Refs #21450.
Fixed #23278 -- Documented django.db.backends.schema logger