Fix "semicolon" in docs
Merge pull request #1321 from bfirsh/semicolon-colon-docs

Fix "semicolon" in form docs
A couple more semicolon -> colon fixes; refs #18134.
Fixed #20691 -- Added a note for __str__() vs. __unicode__() and Python 3.

Thanks garrison for the suggestion.
Added check when fetching and updating translations from Transifex

So as syntax errors in po files don't go unnoticed. Refs #20695.
Fixed #20687 -- Added documentation for django.core.signing API.

Thanks Baptiste Mispelon for the suggestion.
Fixed #20609 -- Documented how to use request.user with RequestFactory

Thanks michel@ for the suggestion.
Fixed #20675 -- `check_password` should work when no password is specified.

The regression was introduced by 2c4fe761a. refs #20593.
Fixed #20625 -- Chainable Manager/QuerySet methods