Issue #2072647 by thedavidmeister, herom, jwilson3, Cottser, LinL: #theme 'maintenance_page' should support render arrays in #content.

Issue #1934772 by sun, andypost, tim.plunkett: Filter module is not required, but is marked as required.

Issue #922696 by mgifford, EvanDonovan, LewisNyman, stpaultim, jensimmons: New methods, standards for describing core themes on themes admin page (was Theme screenshots do not have adequate alt text...).

Issue #2045931 by Sam152, joelpittet, LinL, Sutharsan, adsw12: Replace all module_exists() deprecated function calls.

Issue #2182315 by joachim: Simpletest verbose output doesn't show end result of a drupalPostAjaxForm().

Issue #2181863 by karthik kumar bodu: Xpath method on \Drupal\simpletest\WebTestBase has an undocumented  parameter.

Issue #2190643 by Berdir, amateescu, Xano, yched: Serializing the container is a very very bad idea, let's prevent it?.

Issue #2171683 by sun, alexpott, tstoeckler, larowlan: Remove all Simpletest overrides and rely on native multi-site functionality instead.

Issue #2090509 by yched, swentel, Wim Leers: Optimize entity_get_render_display() for the case of 'multiple entity view'.

Issue #2081963 by mr.baileys, dawehner: Shortcut add/remove link on titles don't work on route only pages.

Revert "Issue #2171683 by sun, tstoeckler, larowlan: Remove all Simpletest overrides and rely on native multi-site functionality instead."

This reverts commit 91db25eb. Broke web
tests.

Issue #2002168 by klausi, Github sync, effulgentsia: Convert form validation of terms to entity validation.

Issue #2147153 by dawehner, alexpott, Xano: Replace the last instance of $_GET/$_POST; Create a special exception listener / exception controller which allows to use POST requests.

Issue #2171683 by sun, tstoeckler, larowlan: Remove all Simpletest overrides and rely on native multi-site functionality instead.

Issue #2084907 by clemens.tolboom, chris_hall_hu_cheng, Noe_, discipolo, Xano, patrickd, damiankloip, alexpott | Jeff Burnz: Hook_views_pre_render() is broken if your theme implements a base theme.

Issue #2165155 by Berdir, tim.plunkett: Change $entity_type to $entity_type_id and $entity_info to $entity_type/$entity_types.

Issue #1895018 by Berdir, danylevskyi, ceardach, alexpott: Convert token API and node token tests to DrupalUnitTestBase.

Issue #2182423 by Berdir, joelpittet: Key_value_expire doesn't get reset and balloons the PDO execution time for form pages.

Issue #2184707 by pwolanin, Berdir: Misnamed variable in content_translation_menu_link_defaults_alter().

Issue #1926344 by jhodgdon, maggo, mdrummond, alexpott, Cottser, dimboz | jenlampton: Consolidate search-result.html.twig and search-results.html.twig.

Issue #2191101 by Cottser, thedavidmeister | xjm: Replace calls to theme() with drupal_render() in Views plugins.

Issue #2163919 by yched, mtift: Optimise Config EntityQueries in case there are conditions on the 'id'.

Issue #2181655 by malionek: Extra semicolon & wrong spacing between dot and concatenated parts in common.inc.

Issue #2165835 by yched, tstoeckler: Rename EntityDisplay to EntityViewDisplay in accordance with its interface.

Issue #1490402 by LewisNyman, nod_, mcjim, mdrummond, rteijeiro, jessebeach, Bojhan, ry5n: Redesign tabs and the content header.