This reverts commit 8ce27f22.

Issue #2045923 by drupalrv, tim.plunkett: Replace all module_invoke_all() deprecated function calls in procedural code.

Issue #1998204 by tim.plunkett: Fixed config_install_default_config() is not safe to use in hook_update_N().

Issue #1856976 by andypost, Soul88, ACF, aspilicious, vijaycs85, dawehner: Convert language_count() to the state system.

Issue #1833022 by e0ipso, plach, YesCT, kfritsche, penyaskito, vijaycs85, nod_, cam8001: Only display interface language detection options to customize more granularity.

Issue #1754246 by webflo, swentel, penyaskito, andypost, alexpott, YesCT, dagmar: Languages should be configuration entities.

Issue #1988508 by katbailey: Stop pretending we support Symfony bundles when we really just have service providers.

Issue #1872876 by chx, fubhy, dawehner, alexpott, tim.plunkett: Turn role permission assignments into configuration.

Issue #1668866 by ParisLiakos, aspilicious, tim.plunkett, pdrake, g.oechsler, dawehner, Berdir, corvus_ch, damiankloip, disasm, marcingy, neclimdul: Replace drupal_goto() with RedirectResponse.

Issue #1852454 by patrickd, xjm, YesCT, Berdir, amateescu, Pancho, djroshi, dealancer, Wim Leers, jessebeach: Restrict module and theme name lengths to 50 characters.

Issue #1813762 by ParisLiakos, Jose Reyero, YesCT, japicoder, attiks: Introduce unified interfaces, use dependency injection for interface translation.

Issue #1998576 by beejeebus, alexpott, swentel: Make the config import process use full config trees again.

Issue #1957154 by joates, ayelet_Cr, xjm | Berdir: Replace calls to drupal_container()->get('module_handler()') service with Drupal::moduleHandler().

Issue #2002732 by Froelund, diarmy, drupalmonkey: Improve code maintainability by removing unused local variables - core/includes/update.inc.

Issue #1827448 by RobLoach, sun, jbrown, tstoeckler: Use __DIR__ instead of DRUPAL_ROOT where possible/sensible.

Issue #1712250 by alexpott, n3or, cam8001, vijaycs85, Albert Volkman, jibran, heyrocker, chx: Convert theme settings to configuration system.

Issue #1937600 by Berdir, rootatwc | webchick: Determine what services to register in the new Drupal class.

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 #1798734 by Berdir, ACF, leschekfm, heyrocker, alexpott: Convert drupal_private_key() to the configuration system.

Issue #1751348 by heyrocker, vijaycs85, julien, Gábor Hojtsy: Convert locale settings to configuration system.

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.

Issue #1317628 by Albert Volkman, Gaelan, disasm, mjonesdinero, xjm: Clean up for API docs in include files starting with n-z

Issue #1792536 by chx, Berdir, sun, David_Rothstein: Remove the install backend and stop catching exceptions in the default database cache backend.

Issue #1158322 follow-up by chx: Fixed htmlspecialchars() expects parameter 1 to be string, array given errors in exception backtraces.

Issue #1817182 by andypost, alexpott, yched: Add upgrade path tests for contact category config conversion.

Issue #1817182 by andypost, alexpott, yched: Add upgrade path tests for contact category config conversion.

Issue #1292470 by sun, tim.plunkett, Berdir, moshe weitzman, pcambra, Niklas Fiekas, andypost et al: Convert user pictures to Image Field.

Issue #1825466 by justafish, sun, alexpott: Allow NestedArray::mergeDeepArray() to preserve integer keys for the purpose of merging config data.