Issue #2453761 by Gábor Hojtsy: Views numeric formatter's plural formatting setting incompatible with many languages

Issue #2459971 by Gábor Hojtsy: The langcode key on configuration files is not explicit in configuration schema

Issue #2457887 by prateekMehta, stefan.r, rpayanm, alexpott: Use Utility\SafeMarkup class instead of Utility\String for placeholder(), checkPlain(),format() functions

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 #2428703 by Wim Leers: Add a 'user.permissions' cache context (was: "Should cache contexts be able to associate a cache tag?")

Issue #2443783 by gaurav_varshney, fotuzlab: Remove language_load(), language_list() and language_default() from bootstrap.inc

Issue #2298687 by tstoeckler, Jose Reyero, hussainweb, rpayanm: Sequence and Mapping implement interfaces incorrectly, make them honest about what they support

Revert "Issue #2298687 by tstoeckler, Jose Reyero, hussainweb, rpayanm: Sequence and Mapping implement interfaces incorrectly, make them honest about what they support"

This reverts commit 43370336.

Issue #2298687 by tstoeckler, Jose Reyero, hussainweb, rpayanm: Sequence and Mapping implement interfaces incorrectly, make them honest about what they support

Issue #2395627 by tstoeckler, Leksat, webflo, Gábor Hojtsy: Do not remove 0 from config translation data

Issue #2260061 by Jelle_S, attiks, Wim Leers, mdrummond, mgifford, holist: Responsive image module does not support sizes/picture polyfill 2.2

Issue #2406543 by alexpott: Remove ConfigFactory::setOverrideState and ConfigFactory::getOverrideState()

Issue #2407907 by YesCT, mr.york: Configuration translation entity listings displays items overriden

Issue #2225427 by ianthomas_uk, martin107, JeroenT, LoMo: Remove remaining uses of deprecated language functions (mostly in object oriented code)

Issue #2350837 by dawehner, Berdir, larowlan, Wim Leers: Convert most usages of EntityInterface::getSystemPath() to use routes

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

Issue #2137595 by olli, idebr, mitrpaka: 'Create @name' page title uses override-free configuration (eg. not localized) instead of the overridden configuration (eg. localized)

Issue #2281645 by dawehner, andypost: Make entity annotations use link templates instead of route names

Issue #2030571 by calebtr, daffie, filijonka, YesCT, Thomas Brekelmans, alexpott, Mile23, tadityar, Sharique, tim.plunkett, boztek: Expand Block with methods

Issue #2281619 by dawehner, tim.plunkett: Convert most direct usages within module code of routing related request attributes to use RouteMatchInterface instead

Issue #2396739 by hussainweb, Mile23: Clean-up config_translation module test members - ensure property definition and use of camelCase naming convention

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

Issue #2113243 by rpayanm, Xano, tstoeckler: Rename BaseFormIdInterface::getBaseFormID() to BaseFormIdInterface::getBaseFormId()

Issue #2226863 by cs_shadow, filijonka, joelpittet, pguillard: Update stale references to theme functions that have been converted to Twig

Issue #2144413 by tstoeckler, YesCT, robertdbailey, webflo, Schnitzel, Wim Leers, kfritsche, Jose Reyero, Gábor Hojtsy, prodosh: Config translation does not support text elements with a format

Issue #2288911 by znerol, effulgentsia: Use route name instead of system path in user maintenance mode subscriber

Issue #2321385 by alexpott, bircher, amateescu, swentel, benjy: Fixed Creation of node body field in postSave() incompatible with default config and overrides.

Issue #2135101 by Gábor Hojtsy, stefank, YesCT: Fixed Expand test coverage on configuration translation tabs.

Issue #2349651 by larowlan, yannisc: Fixed Default contact form does not send email as email recipient is not set during the installation.

Issue #2341341 by YesCT, martin107, vijaycs85, fran seva: Change public 'name' property access on languages to getName() and add back setName().

Issue #2346129 by tstoeckler: Introduce a TraversableTypedDataInterface and use that for typehinting instead of ArrayElement.

Issue #2340667 by YesCT, Pedro Lozano, alexpott, martin107: Protect Drupal\Core\Language\Language::id, and use getId().

Issue #2347465 by tim.plunkett, dawehner, cilefen: Convert all instances of #type link/links to convert to use routes.

Issue #2230091 by dawehner, Berdir, marthinal, martin107: Fixed Route rebuilding is not guaranteed to finish in time for the next request.