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 #20690 -- Mentioned LOCALE_PATHS earlier in translation docs.

Thanks rene@ for the suggestion.
Fixed #12579 -- Noted QuerySet.get_or_create() depends on database unique constraints.

Thanks timmolendijk, jdunck, vijay_shanker, and loic84.
Fixed #20429 -- Added QuerySet.update_or_create

Thanks tunixman for the suggestion and Loic Bistuer for the review.