Merge pull request #1052 from dstufft/bcrypt-python3

BCrypt on Python3
Don't hardcode primary keys in gis tests.
Fixed embarrassing typo.
Fixed #20249 - Removed a "feature" in the tutorial that doesn't actually work.

Thanks bmispelon for the report and draft patch.
Fixed #20136 - Fixed and expanded the docs for loaddata and model signals.

Thanks brandon@ and Anssi for the report.
Fixed #20397 - Cleaned up issue with quotation marks in documentation
Updated test failure example.
Merge pull request #1058 from svisser/ticket_20397

Fixed #20397 - Cleaned up issue with quotation marks in documentation
Fixed #20398 - Added language selection code to example in documentation

Thanks ggbaker for the suggestion and Simeon Visser for the patch.
Merge pull request #1053 from makto/patch-1

Fixed #20394 - Clarified argument of get_user in docs
Recommend using the bcrypt library instead of py-bcrypt

* py-bcrypt has not been updated in some time
* py-bcrypt does not support Python3
* py3k-bcrypt, a port of py-bcrypt to python3 is not compatible
  with Django
* bcrypt is supported on all versions of Python that Django
  supports
Fixing a minor spelling mistake in the queryset documentation
Merge pull request #1064 from Wilfred/master

Minor spelling fix
Merge pull request #1039 from cannona/master

Clarified what unique_for_date considers
Merge pull request #1062 from dstufft/switch-bcrypt-recommendations

Recommend using the bcrypt library instead of py-bcrypt
Fixed #19934 - Use of Pillow is now preferred over PIL.

This starts the deprecation period for PIL (support to end in 1.8).
Removed unicode literals from PIL compat.
Fixed #20165 - Updated testing example to use django.test.TestCase.

Thanks Lorin Hochstein.
Improved the timezone middleware example slightly.

This change avoids having the timezone leak from a request to the next.
Don't unregister OSMGeoAdmin, other tests rely on it.