refs #17365, #17366, #18727.

Switched {% cycle %} and {% firstof %} tags to auto-escape their variables per deprecation timeline.

refs #17906.

refs #20288.

refs #21386.

refs #4592.

refs #19689.

refs #19934.

refs #5789.

refs #15201.

Also removed related utility functions:
* django.utils.html.fix_ampersands
* django.utils.html.clean_html

Also removed the backward compatible shims introduced to rename the
attributes ChangeList.root_query_set and ChangeList.query_set.

Thanks to bak1an for the patch.

Fixed #21840 -- Moved dunder methods from SimpleLazyObject to LazyObject...

Thanks bmispelon for the suggestion.

The test previously failed with the error:
(1170, "BLOB/TEXT column 'name' used in key specification without a key length")

Some platforms with os.name == 'posix' do not have the
fcntl module, e.g. AppEngine.

refs #19373.

Fixes #22281

Thanks charettes for the suggestion.