Thanks Aymeric for the initial patch and Carl for review.

Bail early if the input is a string since that's the most common case.

Thanks Josh, Anssi, and Carl for reviews and advice.

Forwardport of 3ded51bc from stable/1.8.x

Thanks to Kevin Turner for the report and Tim for the review.

Removed the bit about not allowing assignment to variables
because simple_tag now allows this.

This is consistent with the behavior of Django 1.7.x and earlier.

Thanks to Jamie Matthews for finding and explaining the bug.

Forwardport of 8c8a6d8a from stable/1.8.x

psycopg2 now publishes binary wheel files for Windows
so you can install it using pip.

Thanks Jacek Bzdak for indepdently contributing a similar fix.

This fixes a regression from refs #25496.

This only happens if USE_TZ = False and pytz is installed (perhaps not
the most logical combination, but who am I to jugde?)

Refs #23714 which essentially fixed the same problem when USE_TZ = True.

Thanks Florian and Carl for insisting until I wrote a complete patch.

To improve consistency, sample URL names that had underscores
in them now use dashes instead. That excludes URL names that
have some relation to the code, such as those generated by
the admin.

Thanks guettli for reporting this.

This was a possible confusion source with column name arguments.
Thanks Sergey Fedoseev for the suggestion.

Thanks Iacopo Spalletti for the report and testing.