Issue #2521906 by mErilainen, LewisNyman, Bojhan, eliza411, ivanstegic, lunk_rat, nickrosencrans, stpaultim, Mark LaCroix, webchick: Add default configuration to support h2-h6 level headings

Issue #2535082 by alexpott, jhedstrom, xjm, plach, Fabianx, effulgentsia, Berdir: Allow hook_update_N() implementations to run before the automated entity updates

Issue #2509300 by dawehner, catch, larowlan: Path alias UI allows node/1 and /node/1 as system path then fatals

Issue #1392754 by tss, justAChris, jhodgdon: Comply with new documentation standards for @file for namespaced class files

Issue #2392293 by bircher, tim.plunkett, alexpott, cilefen, gobinathm: Refactor hook_system_info_alter implementations to use ModuleUninstallValidatorInterface

Issue #2470807 by LewisNyman, Dom., davidhernandez, emma.maria, lauriii, jp.stacey: Rename the default "Messages" region for all themes to "Highlighted"

Revert "Issue #2470807 by LewisNyman, Dom., davidhernandez, emma.maria, jp.stacey, lauriii: Rename the default "Messages" region for all themes to "Highlighted""

This reverts commit 249e520b.

Issue #2468767 by eiriksm, Gábor Hojtsy: English config source strings are saved as custom translations in locale in foreign install

Issue #2470807 by LewisNyman, Dom., davidhernandez, emma.maria, jp.stacey, lauriii: Rename the default "Messages" region for all themes to "Highlighted"

Issue #2473709 by nicoloye, marcvangend, pjbaert, yoroy, webchick: Do not use SERVER_NAME as default value for the site name

Issue #2432791 by alexpott, vijaycs85, tim.plunkett, joshtaylor, Fabianx, Berdir, yched, bojanz: Skip Config::save schema validation of config data for trusted data.

Issue #2368987 by Wim Leers, Berdir, Schnitzel, epari.siva, bircher, vijaycs85, likin: Move internal page caching to a module to avoid relying on config get on runtime

Issue #1847596 by amateescu, amitaibu, YesCT, Berdir, David_Rothstein, xjm, rteijeiro, ParisLiakos, webchick, Wim Leers, yched, jhodgdon, Bojhan: Remove Taxonomy term reference field in favor of Entity reference

Issue #2212069 by Gábor Hojtsy, pjonckiere, rteijeiro, cilefen: Non-English Drupal sites get default configuration in English, edited in English, originals not actually used if translated

Issue #2090115 by alexpott, xjm: Don't install a module when its default configuration has unmet dependencies

Issue #2303765 by davidhernandez, larowlan, mgifford: Make the default 'alt' attribute for Image fields required

Issue #2148319 by crazyrohila, juankvillegas, Manjit.Singh, poojakural, Chloe Chen, joshtaylor: h2 on footer blocks must be hidden by default but must show when its enable

Issue #2289917 by Wim Leers, mdrummond, lauriii, Manuel Garcia, emma.maria, Scionar, davidhernandez: Convert "messages" page element into blocks

Issue #2435075 by dawehner: Implement admin role as a flag on the role storage, simplify permissions page, remove user_modules_installed

Issue #2417647 by Wim Leers, effulgentsia: Add leading slash to paths within 'user-path:' URIs, to allow 'user-path:' URIs to point to the <none> route

Issue #1959806 by amateescu, jibran, goldorak, Wim Leers, yched, dawehner: Provide a generic 'entity_autocomplete' Form API element

Issue #2402639 by Katiemouse, nitvirus, lakshminp, dernetzjaeger, emma.maria, gippy, kporras07, john guant, Prashant.c: Rename the footer regions in Bartik

Issue #2412509 by kgoel, pwolanin, Wim Leers, larowlan, effulgentsia, dawehner, xjm: Change LinkItem.uri to type 'uri' rather than 'string' and introduce user-path: scheme

Issue #2306407 by lauriii, penyaskito, mortendk, pakmanlh, Wim Leers, ypogue: Remove breadcrumb from page template

Issue #2235457 by dawehner, amateescu, hussainweb, Berdir, benjy, Wim Leers, lokapujya, RavindraSingh, Ryan Weal, jibran, Jalandhar: Use link field for shortcut entity

Issue #2094499 by amateescu: Convert "Manage (form) display" forms to be the official entity edit forms for EntityView[Form]Display objects

Issue #2392319 by alexpott, effulgentsia: Config objects (but not config entities) should by default be immutable

Issue #2384481 follow-up by larowlan: [HEAD BROKEN] Fix references to node type properties in Seven theme.

Issue #2357801 by dawehner, amitgoyal: File field default values are not deployable -- use UUIDs for the default file

Issue #2395395 by alexpott, effulgentsia, Gábor Hojtsy: TestBase lacks a config method to be used consistently in tests

Issue #2248977 by Berdir: Complete support for multi-value base fields in ContentEntitySchemaHandler and use it for the user.roles field