Removed BaseDatabaseCreation.set_autocommit per deprecation timeline.
Fixed #22307 -- Fixed SpooledTemporaryFile bug in File class.

Added condition to prevent checking the existence of a file name of a
file like object when the name attribute is None. This is necessary
because a SpooledTemporaryFile won't exist on the file system or have a
name until it has reached its max_size. Also added tests.
Removed hard-coded help_text for ManyToManyFields that use a SelectMultiple widget

Per deprecation timeline; refs #9321.
Removed warning for Widget.is_hidden property.

refs #22137.
Removed backwards compatibility code to call field.widget._has_changed()

This logic should be moved to field._has_changed() as described
in ebb504db692cac496f4f45762d1d14644c9fa6f - refs #16612.
Removed unused imports.
Fixed #22302 -- Updated Finnish locale formats
Improved strip_tags and clarified documentation

The fact that strip_tags cannot guarantee to really strip all
non-safe HTML content was not clear enough. Also see:
https://www.djangoproject.com/weblog/2014/mar/22/strip-tags-advisory/
Avoided transactional DDL on castrated databases.

Fixed a test failure that appeared after 753a22a6, although the bug
existed before that commit.

Refs #22308.
Added release note about strip_tags improvement
Made ModelForms raise ImproperlyConfigured if the list of fields is not specified.

Also applies to modelform(set)_factory and generic model views.

refs #19733.
Avoided transactional truncates on amateur databases.

Fixed a test failure that appeared after 753a22a6, although the bug
existed before that commit.

Refs #22308.
Tweaked strip_tags tests to pass on Python 3.3
Fixed #22294 -- Prevented converting length filter output to string

Thanks Steve Pike for the report.
Fixed #22256 -- Replaced bad fallback for missing PATH

Thanks Baptiste Mispelon for the review.
Fixed #22241 -- Selectively added line breaks in admin read-only fields

When content is supposed to contain HTML, we do not try to add
line breaks in read-only contents.
Thanks Alexander Todorov for the report.
Fixed a failing test introduced in 918a16bc4c099ab0cae72a231de3e99e2a9d02cb.

Refs #22307.
Removed an unused variable.
Fixed #20684 -- Added support for HTML5 boolean attributes to form widgets.
Made m2m fields form help_text munging specific to admin widgets.

Refs #9321 and follow-up to e80de93af6a0a21a9063a55c4d6d20e3927243e9.