Issue #2740983 by VitalyM, alexpott: Configuration system doesn't allow importing a single item from a non-default collection

(cherry picked from commit d97ed166bd3a335fd7cf94d6b5e0a715955364d2)

Issue #2702227 by claudiu.cristea, jeroen.b, marco.giaco: Image styles for private files are serving the original instead of derivative

(cherry picked from commit bba2fda3)

(cherry picked from commit e0258752)

Issue #2781673 by Bambell, Berdir: MenuLinkContent menu links can not be set to no parent once they had one

(cherry picked from commit b2e94794)

Issue #2784463 by martin107, naveenvalecha, tim.plunkett: Convert outside_in_page_(top|bottom)() to a #theme_wrappers

(cherry picked from commit 4beaddb7)

(cherry picked from commit 6fc9b0d8)

(cherry picked from commit 5730984d)

(cherry picked from commit bf919883)

(cherry picked from commit 73333c5b)

Issue #2781207 by timmillwood, dawehner: Use class resolver for abstracted Content Moderation classes

(cherry picked from commit fe33c4b9)

(cherry picked from commit bd2772d9)

Issue #2783393 by Mile23: Fix 'Drupal.Commenting.FunctionComment.IncorrectParamVarName' coding standard

(cherry picked from commit 08b7a3fb)

Issue #2406533 by alexpott, willzyx, olli, Berdir, DamienMcKenna, Dom., Crell, Wim Leers, mdrummond, mirzu, enjoyiacm, catch: edit-form, delete-form etc. <link> tags added on /node/{node} are invalid according to W3C Validator

(cherry picked from commit 182f0316)

(cherry picked from commit 0a8686ac)

(cherry picked from commit da0645c1)

(cherry picked from commit 47a7f18b)

Issue #2783849 by Shashwat Purav, kiamlaluno: hook_filetransfer_info() documentation has not been updated for Drupal 8

(cherry picked from commit db998a72)

(cherry picked from commit 56a347ca)

(cherry picked from commit e51f98e1)

(cherry picked from commit bc3bb246)

(cherry picked from commit 0d00a94b139602d9280360dc2977dbc989c6ef1e)

Issue #2753941 by tedbow, tim.plunkett, tkoleary, SKAUGHT, drpal, effulgentsia, andrewmacpherson, webchick, xjm, Bojhan, Gábor Hojtsy, Wim Leers, catch, nod_: [Experimental] Create Outside In module MVP to provide block configuration in Off-Canvas tray and expand site edit mode

(cherry picked from commit 42b81c64)

Issue #2783749 by alexpott, bircher: [regression] Config directories should be created by installer if present in setings.php and if possible

(cherry picked from commit 9e2f220d)

(cherry picked from commit ce17b237)

Issue #2780549 by andrewbelcher, alexpott, mpdonadio: FormattedDateDiff::$maxAge never applied to caches

(cherry picked from commit 1bd3a04d)

(cherry picked from commit 98889d33)

(cherry picked from commit 24343f97)

Revert "Issue #2780549 by andrewbelcher, alexpott, mpdonadio: FormattedDateDiff::$maxAge never applied to caches"

This reverts commit f465ed32.

Issue #2780549 by andrewbelcher, alexpott, mpdonadio: FormattedDateDiff::$maxAge never applied to caches

(cherry picked from commit abe69518)

(cherry picked from commit f24af6a0)

Revert "Issue #1267508 by fietserwin, lisa.ugray, daffie, chx, Crell: Subselects don't work in DBTNG conditions, except when used as value for IN"

This reverts commit 22a241ca.

(cherry picked from commit a0096f1c)

(cherry picked from commit 45b845de)

Issue #2778673 by neclimdul: UnitTestCase::getStringTranslationStub() incorrectly documents its return type

(cherry picked from commit 24630471)

Issue #2392729 by AlviMurtaza, Sumit kumar, Manjit.Singh, simply021, skippednote, studiozut, Vidushi Mehta, vipulaSD, vova_ob, deepakkumar14, Truptti, Maninders, vsawant, meeli, Cottser, jeffrey.vargas, lamaxi, LewisNyman, emma.maria: Optimize Seven's select boxes for small screens

(cherry picked from commit b184ba67)

Issue #2640464 by samuel.mortenson, Chernous_dn, droplet, Wim Leers: Links styled as buttons not placed inside Dialog's button pane — prevents "cancel" link/button from showing up

(cherry picked from commit 1aa64583)

(cherry picked from commit 8824b867)

(cherry picked from commit 27b2c4ff)

Issue #2776071 by damiankloip, neclimdul, Mixologic: run-tests.sh does not return a non zero status when tests fail with exception

(cherry picked from commit 74d2937c)

(cherry picked from commit 51a76efb)