Fixed minor warnings in tests.
Fixed #19989 -- Suppressed UnicodeWarning during BinaryField validation

Thanks Aymeric Augustin for the report and Simon Charette for the
review.
Fixed #19994 -- Typo.

Thanks akshar for the report.
Used more precise test assertions.
One more EMPTY_VALUES replacement following 22be90dd17

Thanks Loic Bistuer for catching this omission. Refs #19989.
Update link to django-mssql project
Merge pull request #884 from manfre/patch-1

Fixed #19996 - Updated link to django-mssql project in docs.
Fixed #19543 -- implemented SimpleLazyObject.__repr__

Thanks to Florian Hahn for the patch
PEP8 cleanup of functional.py
Merge pull request #882 from loic/testfix

Fixed minor warnings in tests.
Fixed #19951 -- Admin: Invalid model PK values shouldn't cause 500 status.

Avoid ValueError in admin when passing a string as PK for an inherited
model with an integer PK field.

Thanks ikks for the patch. See also #11191.