Issue #2308821 by tim.plunkett: Replace FormErrorInterface with $form_state->setErrorByName() and $form_state->setError().

Issue #1825952 by Fabianx, joelpittet, bdragon, heddn, chx, xjm, pwolanin, mikey_p, ti2m, bfr, dags, cilefen, scor, mgifford: Turn on twig autoescape by default

Issue #2284103 by alexpott, fabpot, damiankloip, Xano, Xen, Berdir: Fixed Remove the request from the container.

Issue #2239969 by znerol, alexpott, neclimdul, sun: Fixed session of (UI) test runner leaks into web tests.

Issue #2016629 by larowlan, neclimdul, sun, alexpott, jibran, ParisLiakos, donquixote, effulgentsia, msonnabaum: Refactor bootstrap to better utilize the kernel.

Revert "Issue #2016629 by larowlan, neclimdul, sun, alexpott, jibran, ParisLiakos, donquixote, effulgentsia, msonnabaum: Refactor bootstrap to better utilize the kernel."

This reverts commit cda051c4.

Issue #2016629 by larowlan, neclimdul, sun, alexpott, jibran, ParisLiakos, donquixote, effulgentsia, msonnabaum: Refactor bootstrap to better utilize the kernel.

Issue #2249113 by tstoeckler, jessebeach: Use an entity save instead of db_insert() in user_install().

Issue #2240007 by sun, YesCT, mr.baileys | Gábor Hojtsy: Regression: early installer is not in RTL after selecting RTL language.

Issue #2247281 by sun, pwolanin: Installer checks wrong config storage to verify installation state.

Issue #1067408 by alexpott, Jalandhar, jessebeach, Désiré, neetu morwani, dawehner, sun: Themes do not have an installation status.

Issue #2221695 by brantwynn, ianthomas_uk, grom358, ParisLiakos, Jalandhar: Remove uses of deprecated URL functions.

Issue #2161591 by pwolanin, beejeebus, sun: Change default active config from file storage to DB storage.

Issue #2228341 by sun, znerol, skipyT, ParisLiakos: Objectify session management functions + remove session.inc.

Revert "Issue #2218039 by sun, dawehner: Render the maintenance/install page like any other HTML page."

Broke update.php.

This reverts commit 10b03890.

Issue #2169765 by philipz, Sutharsan, ckrina, c_lehel, LewisNyman: Redesign update.php to be more consistent with the installation process.

Revert "Issue #2169765 by philipz, Sutharsan, ckrina, c_lehel, LewisNyman: Redesign update.php to be more consistent with the installation process."

This reverts commit 728aad1d.

Issue #2169765 by philipz, Sutharsan, ckrina, c_lehel, LewisNyman: Redesign update.php to be more consistent with the installation process.

Issue #340723 by ParisLiakos, sun, Berdir, glennpratt, Cottser, swentel, alexpott, tstoeckler, Xano, tim.plunkett, BassistJimmyJam | beejeebus: Make modules and installation profiles only require .info.yml files.

Revert "Issue #340723 by ParisLiakos, sun, Berdir, glennpratt, Cottser, swentel, tstoeckler, Xano, tim.plunkett, BassistJimmyJam: Make modules and installation profiles only require .info.yml files."

This reverts commit b4c561d0.

Issue #340723 by ParisLiakos, sun, Berdir, glennpratt, Cottser, swentel, tstoeckler, Xano, tim.plunkett, BassistJimmyJam: Make modules and installation profiles only require .info.yml files.

Issue #1351352 by sun, lucascaro, Gábor Hojtsy, rupertj: Distribution installation profiles are no longer able to override the early installer screens.