Added a test to verify headers set by default middleware; refs #23939.
Removed redundant numbered parameters from str.format().

Since Python 2.7 and 3.1, "{0} {1}" is equivalent to "{} {}".
Fixed typo in docs/ref/request-response.txt.
Refs #18586 -- Split up model_inheritance.ModelInheritanceTest
Converted recently refactored templates tests to SimpleTestCase.

These test methods don't need DB setup/teardown.

Refs #23768 and b872134b.
Documented a current limitation of multiple table annotation; refs #10060.
Fixed a typo in aggregation docs.
Fixed typo in aggregation docs link.
Fixed #23911 -- Added support for buffer file uploads in the test client
Merge branch 'master' of https://github.com/django/django