Revert "Issue #2489162 by googletorp, Haza, mdrummond, DuaelFr, swentel: Can configure responsive image formatter to cause fatal error"

This reverts commit c8702065.

Issue #1739846 by dawehner, Bès, DuaelFr, madhavvyas, damiankloip, aspilicious, fastangel, tim.plunkett, xjm: Tests taxonomy argument validator plugin

Issue #2463659 by andypost, Wim Leers, rpayanm, Fabianx, googletorp: Regression test coverage: integration test for an uncacheable menu link that depends on session data

Issue #2550287 by cilefen, hexabinaer, legolasbo, dawehner: Expand display "Comment" trim from 10 to 80 characters

Issue #2558615 by stefan.r: Error message in MySQL client version check shows server version instead of client version

Issue #2493989 by Antti J. Salminen, lauriii, slashrsm: template_preprocess() and other preprocess functions are called even for theme hooks implemented as functions

Issue #2349011 by Fabianx, Wim Leers: Support placeholder render strategies so contrib can support BigPipe, ESI…

Issue #2560411 by davidhernandez: The same CSS classes are being added to the field wrapper and field item

Issue #2555169 by TR: API documentation should not suggest using deprecated function format_string()

Issue #2542748 by plach: Follow-up to Automatic entity updates can fail when there is existing content, leaving the site's schema in an unpredictable state

Issue #1617918 by pfrenssen, tea.time: Test that no validation errors occur for anonymous users when $form['#token'] == FALSE

Issue #2470145 by David_Rothstein, rbmboogie, tbradbury, johnpicozzi, ifrik: Fix text for update manager checkbox for disabled extensions

Issue #2558187 by sdstyles: Remove usage of UrlGeneratorInterface::generateFromPath() in language module

Issue #2349431 by talhaparacha, Cyberwolf, bhavinvora, pjonckiere: Docs mention support for PUT instead of POST

Issue #2477337 by jhedstrom, dawehner, tim.plunkett, sumitmadan: Add test to ensure saving a menu item with internal path instead of entity reference does not lose hierarchy

Issue #2468713 by StryKaizer, jhedstrom, rootwork, dawehner, paulmckibben, sumitmadan, tim.plunkett: Internal/custom menu links force-reset to the top of their menus on cache rebuild

Revert "Issue #2468713 by StryKaizer, jhedstrom, rootwork, dawehner, paulmckibben: Internal/custom menu links force-reset to the top of their menus on cache rebuild"

This reverts commit 5cd3b685.

Issue #2468713 by StryKaizer, jhedstrom, rootwork, dawehner, paulmckibben: Internal/custom menu links force-reset to the top of their menus on cache rebuild

Issue #2561201 by larowlan, cilefen, Sutharsan: Fatal error when creating a shortcut in a new shortcut set

Issue #2551907 by Wim Leers, dawehner: Follow-up for #2483183: make the Breadcrumb value object use composition instead of inheritance

This reverts commit 5823083e.

Issue #2400407 by DuaelFr, webchick, hussainweb, klausi, dawehner, cilefen, catch, kim.pepper, iMiksu, MustangGB: [meta] Ensure vendor (PHP) libraries are on latest stable release

Issue #2540850 by tim.plunkett, larowlan, kattekrab, DuaelFr, emma.maria, Wim Leers: (regression) EditorImageDialog alignment & captioning are not working