Fixed #21235 -- Disabled savepoints for old versions of SQLite.

Thanks Ramiro for the report.
Re-added link to SQLite notes from DB section of install doc.
Fixed #21236 -- Allowed migrations to work with unique_together tuples.

Thanks hjwp for the report.
Fixed #18263 -- Corrrected handling of hidden fields in tabular admin inlines.

Thanks hvdklauw for the report and patch.
Fixed #21241 -- Avoid extraneous JOINs in admin changelist search.
Added a link in admin branding block to admin index.

Refs #13749 and #21220.
Revert "Fixed #21241 -- Avoid extraneous JOINs in admin changelist search."

This reverts commit 698dd82eee1cb83f51d4cd39546461bf76976b5e.

The patch introduced a backward incompatible change.
Added min-width for date and time inputs in admin.

refs #21220.
Cleaned up admin CSS for consistency.

* header selected twice -merged
* match indentation throughout
* color names to hex

refs #21220.
Refs #21197 -- Clarified upgrade check message.

Thanks to Carl and Shai for the discussion.
Fixed #21164 -- Added documentation for issue with test users.

The package renaming restores the older package names (which were also the
documented package names). This doesn't affect test discovery because the
module in question doesn't contain any tests.

Thanks to Carl for the design discussion.
Fixed #16822 -- Added RawPostDataException

Thanks jaylett for the patch.
Fixed #20568 -- truncatewords_html no longer splits words containing HTML entities.

Thanks yann0 at hotmail.com for the report.
Fix grammatical errors in email documentation
Merge pull request #1719 from dlo/docs/email-typos

Fix grammatical errors in email documentation
Fixed #21243 -- Corrected exception message in multiple database tests.

Thanks to vajrasky for the report and patch.
Fixed regression introduced by 20472aa827669d2b83b74e521504e88e18d086a1.

The wrong exception was being caught when detecting the presence of GeoIP.
Thanks to ramiro for the report.
Fixed grammar/typos in auth customization docs
Fixed #19924 -- Fixed selectors in actions.js that did not use options.
Fixed #21222 - Documented that 'default' and 'other' must be different databases when running tests.

Thanks vernondcole for the suggestion.