Issue #1664844 by alexpott, cweagans, heyrocker, eojthebrave, ACF, Berdir: Convert image toolkits into plugins.

Issue #1764474 by Berdir, chx, alexpott, pounard, msonnabaum: Make Cache interface and backends use the DIC.

Issue #1547008 by Berdir, Sutharsan: Replace Update's cache system with the (expirable) key value store.

Issue #1209226 by catch, Berdir, miro_dietiker, beejeebus, dagmar: Fixed Avoid slow query for path alias whitelists.

Issue #1843220 by mkadin, dawehner, Crell, effulgentsia, Wim Leers: Convert form AJAX to new AJAX API.

Issue #1845402 by Crell, amateescu, dawehner, klausi, g.oechsler: Change notice: Update menu link access checks for new router.

Issue #1891980 by Berdir, amateescu: Add Service termination API to reliable terminate/shut down services in the container.

Issue #1929136 by Gábor Hojtsy, alexpott, YesCT: Fixed override-free context, move global config overrides back to an event listener.

Issue #1836008 by dawehner, Berdir, alexpott, katbailey, effulgentsia, EclipseGc: Fixed Remove drupal_classloader() use in Drupal\Core\AnnotatedClassDiscovery.

Issue #1763640 by beejeebus, alexpott, Jose Reyero, c31ck, das-peter, YesCT, heyrocker, Gábor Hojtsy: Introduce config context to make original config and different overrides accessible.

Issue #1914366 by vijaycs85, Gábor Hojtsy, alexpott: Move all configuration schema files into a schema subdirectory.

Issue #1910318 by katbailey: Make path resolution the responsibility of a series of PathProcessor classes, rather than one PathSubscriber class.

Issue #1515312 by heyrocker, beejeebus, alexpott, xjm, realityloop, sun: Added snapshots of last loaded config for tracking whether config has changed.

Issue #1798214 by tnightingale, g.oechsler, fubhy, katbailey, effulgentsia, Crell, dipen chaudhary: Upcast request arguments/attributes to full objects.

Issue #1894002 by scor, msonnabaum, effulgentsia: Update vendor libraries and pin them to specific versions in composer.json.

Issue #1899994 by katbailey, plach, YesCT: Disentangle language initialization from path resolution.

Issue #1845546 by fago, EclipseGc, attiks, effulgentsia: Implement validation for the TypedData API.

Issue #1866610 by Jose Reyero, Gábor Hojtsy, effulgentsia, alexpott, aspilicious, YesCT, fago, sun, dawehner, heyrocker, yched, spearhead93: Introduce Kwalify-inspired schema format for configuration.

Issue #1331486 by katbailey, chx, sun, beejeebus, amateescu: Move module_invoke_*() and friends to an Extensions class.

Revert "Issue #1331486 by katbailey, chx, sun, beejeebus, amateescu: Move module_invoke_*() and friends to an Extensions class. Broke core tests after commit."

This reverts commit c80c3e18.

Issue #1331486 by katbailey, chx, sun, beejeebus, amateescu: Move module_invoke_*() and friends to an Extensions class.

Testbot done did brokeded.

This reverts commit 4aaa7252.

Configure the legacy matcher together with a null generator to form a legacy router, which can be included in the Chain Router.