Repositioned two paragraphs in the release notes.
Removed an unused local var
Removed a ton of unused local vars
Hardened the test introduced in ded11aa6. Refs #18766.

Inputs acceptable to time.mktime are platform-dependent.
Further hardening. Refs #18766.
Removed some more unused local vars
Fix #20745: Don't silence TypeError raised inside templates.

Thanks to robin for the report and claudep for the review.
Added a test to show that the user.is_staff check in admin base.html is necessary.

refs #21067
Fixed #20889 -- Prevented email.Header from inserting newlines

Passed large maxlinelen to email.Header to prevent newlines from being
inserted into value returned by _convert_to_charset

Thanks mjl at laubach.at for the report.
Simplify FilterExpression.args_check
Add myself to authors file
Fixed #20707 -- Added explicit quota assignment to Oracle test user
To enable testing on Oracle 12c
Fixed #16895 -- Warned about cost of QuerySet ordering

Thanks outofculture at gmail.com for the suggestion.
Fixed syntax error on Python 3.2; refs #20889.
Fixed spelling; refs #16895.

Thanks Panagiotis Issaris for the report.
Fixed #21063 -- AdminSite app_index should be fail early if the user has no permissions.
Improved release notes for ticket #10164

Thanks Aymeric for the suggestions.

refs #10164
Fixed #21078 -- Handled additional bad Accept-Language header
Fixed #19885 -- cleaned up the django.test namespace

* override_settings may now be imported from django.test
* removed Approximate from django.test
* updated documentation for things importable from django.test

Thanks akaariai for the suggestion.
Fixed #17262 -- Refactored tzinfo implementations.

This commit deprecates django.utils.tzinfo in favor of the more recent
django.utils.timezone which was introduced when Django gained support
for time zones.