Issue #2454649 by Aki Tendo, dawehner: Cache Optimization and hardening -- [PP-1] Use assert() instead of exceptions in Cache::merge(Tags|Contexts)

Issue #2568099 by Wim Leers, mdrummond, mortendk: Follow-up for #2407739: Remove the js-quickedit-main-content class that was added in favor of relying on <main>

Issue #2559955 by Wim Leers, swentel, mdrummond: Ensure that Quick Edit relies less on the structure of the HTML

Issue #2576037 by unqunq, er.manojsharma, sdstyles, martins.kajins, Devaraj johnson, cilefen, Bojhan, Wim Leers: "Sorry" in user-facing errors violates the User Interface Standards

Issue #2090983 by plach, Berdir, yched: ContentEntityInterface::getTranslation() should throw an exception when an invalid language is specified

Issue #2576533 by alexpott, stefan.r, Wim Leers, dawehner, xjm, effulgentsia, catch: Rename SafeStringInterface to MarkupInterface and move related classes

Issue #2550225 by swentel, yched, Wim Leers, aspilicious: quickedit_test_entity_view_alter() creates a non compliant field render array

Issue #2560783 by stefan.r, joelpittet, lauriii, Cottser, Sutharsan, kgoel, justAChris, Gábor Hojtsy, dawehner, jhodgdon, effulgentsia, xjm, andypost, googletorp: Replace !placeholder with :placeholder for URLs in hook_help() implementations

Issue #2407739 by mortendk, davidhernandez, rteijeiro, lduerig, sivaji@knackforge.com: Remove classes from system templates r*.html.twig

Issue #2551105 by Dave Reid: BaseCommand should not be in the quickedit namespace, useful for anything

Issue #2559969 by alexpott: Make SafeStringInterface extend \JsonSerializable so we don't have to do so much string casting

Issue #2551263 by Berdir, nod_: Deleting entity/field models when markup is removed can result in JS error

Issue #2214241 by mortendk, mdrummond, lauriii, galooph, ShaunDychko, jjcarrion, b0unty, joelpittet, scor, amitgoyal, aboros, Manuel Garcia, hkirsman, BLadwin, hussainweb, sushilkr, emma.maria, nlisgo, yched, LewisNyman, davidhernandez, mikl, camoa, dman, dodorama: Field default markup - removing the divitis

Issue #2526326 by borisson_, Berdir, Wim Leers, Xano: Update CacheableMetadata & AccessResult to use RefinableCacheableDependency(Interface|Trait)

Issue #2503963 by Wim Leers, dawehner, nlisgo, mlhess, xjm, effulgentsia, JvE: XSS in Quick Edit: entity title is not safely encoded

Issue #2506581 by alexpott, Wim Leers, Fabianx, xjm, joelpittet, Cottser, dawehner: Remove SafeMarkup::set() from Renderer::doRender

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

Issue #2511472 by Wim Leers, Fabianx, dawehner: Refactor all usages of drupal_render()/Renderer::render() that break #2450993

Issue #2481453 by dawehner, pwolanin, rteijeiro, neclimdul, znerol: Implement query parameter based content negotiation as alternative to extensions

Issue #2395831 by dawehner, fago, martin107, cafuego, YesCT, plach, jibran, larowlan, Wim Leers, effulgentsia, klausi: Entity forms skip validation of fields that are not in the EntityFormDisplay

Issue #2383871 by mgifford, rpayanm, a_thakur, maximpodorov, AohRveTPV, jhodgdon: Spellchecking Drupal - PHP

Issue #2491155 by mikeburrelljr, Mac_Weber, opdavies: Update drupal.org and kernel.org URLs in core modules (Follow-up to 2489912)

Issue #1533366 by nod_, valthebald, Jelle_S, Wim Leers: Simplify and optimize Drupal.ajax() instantiation and implementation

Issue #2383865 by mgifford, pguillard, rpayanm, alexpott, jhodgdon: Spellchecking Drupal - Javascript

Issue #1081266 by stefan.r, mikeytown2, jeroen.b, tsphethean, mfb, joseph.olstad, marcelovani: Avoid re-scanning module directory when a filename or a module is missing

Issue #2343035 by fago, dawehner, larowlan, ianthomas_uk, cilefen, hussainweb, Miroling, jibran, beejeebus, dashaforbes, webmozart, klausi: Upgrade validator integration for Symfony versions 2.5+