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.
Refactored code and tests that relied on django.utils.tzinfo.

Refs #17262.