Thanks oubiga for the suggestion.

Fixed typo and slightly improved error message when db is missing time zone definitions.

Thanks olof.bjarnason at gmail.com for the report.

Refs #21432.

Thanks Enrique Martínez for the report and @bmispelon for the tests.

Fixed #21439 -- Propagated get_user_model exception from get_user

Fixes #21439

Regression introduced by commit 97774429.

Thanks to trac username troygrosfield for the report and test case.

Also removed a sentence that was incorrect: raising a
`ValidationError` inside `Form.clean` doesn't clear the
`cleaned_data` attribute.

Thanks to loic84 and timograham for the review.

Fixed #21388 -- Corrected language code for Frisian

Exposing the level name (e.g. "info") makes it possible to prepend
something to the class name. For example, Twitter Bootstrap has
an alert-info class. This class can now be added to the message
using `class="alert-{{ message.level_tag }}".
Because the level_tag was on the end of the `tags` property, it
could not be used in this fashion when extra_tags were given.

Thanks Gregoire Astruc for the report and furins for the review.

Django also uses locales provided by apps, which also might change. Also when
i18n is disabled, there is no need for watching translation files.

Added description of MySQL Connector/Python

Thanks Bouke Haarsma for the report.

Replaced the custom, untested memoize with a similar decorator from Python's
3.2 stdlib. Although some minor performance degradation (see ticket), it is
expected that in the long run lru_cache will outperform memoize once it is
implemented in C.

Thanks to EvilDMP for the report and Baptiste Mispelon for the idea of
replacing memoize with lru_cache.

Reorganized the MySQLdb section into a "MySQL DB API Drivers" section that describes both MySQLdb and MySQL Connector/Python. Included description of the Django adaptors for these DB API drivers.

Corrected LANGUAGES documentation on how to translate language
names. Now using django.utils.translation.ugettext_lazy instead
of a dummy gettext() function.

Thanks to Salvatore for the report.

Filtering out static file requests in runserver has been judged
arbitrary and can hide some debugging-related activity.
Thanks Roy Smith for the report and Aymeric Augustin for the
review.

Thanks arjan at anymore.nl for the report.

Refs #16969.