Fixed #21692 -- Quote table name when creating it.

The u prefix looks bad on Python 2.

Thanks nedbatchelder and claudep.

Mostly for consistency with MODELS_MODULE_NAME; it's unlikely to change.

Thanks oubiga for the report.

An admin view performed the capitalization in the template, unlike all others.

Refs #10436.

Thanks Aymeric for the suggestion.

Thanks cjerdonek for the suggestion.

It raises ImportError whenever an entry in INSTALLED_APPS points
(directly or indirectly via AppConfig.name) to a non-existing module
and ImproperlyConfigured in all other cases.

Catching ImportError and re-raising ImproperlyConfigured tends to make
circular imports more difficult to diagnose.

Eliminated the app_ prefix that was more confusing than useful.

Previously the _apps/models_loaded flags could remain set to False if
set_installed_apps exited with an exception, which is going to happen as
soon as we add tests for invalid values of INSTALLED_APPS.

Thanks thepapermen for the report and Carl Meyer for the review.

Fixed a crash when executing changepassword command when the user object
representation contained non-ASCII characters.

Removed redundant line

Thanks David Larlet for the suggestion.

Also fixed some Sphinx warnings and improved ReST markup.

Used @cached_property for request.GET and COOKIES

- use code-block:: bash
- prefix the command with $

refs #19321

Thanks carrie.hazelton at altamiracorp.com for the report.

Thanks alex_koval for the report.

Thanks Tim for the review.

Typo fix for exception message.