Issue #2214209 by dawehner, ParisLiakos, xjm: Move _menu_site_is_offine() into the Maintainance subscriber.

Issue #788900 by ParisLiakos, dawehner, effulgentsia, xjm, et al: Deprecate and remove usages of arg().

This reverts commit 0b522f36.

Issue #2273311 by donquixote, xjm: Fixed FieldDefinitionTestBase::getNamespacePath() breaks with PSR-4.

Issue #2273689 by donquixote: Fixed switch-psr4.sh does not reliably remove empty PSR-0 directories.

Issue #2268975 by Gábor Hojtsy, vijaycs85: Fixed named schema elements missing when installing Drupal.

Issue #2224887 by alexpott, Berdir, Gábor Hojtsy, Jalandhar: Language configuration overrides should have their own storage.

Issue #2003766 by InternetDevels, KeyboardCowboy: Fixed Vertical tabs styling is pushed to the right on node edit form.

Issue #2003800 by jhedstrom, filijonka, YesCT, ParisLiakos, steeloctopus, damiankloip, sun, LinL, amateescu: Move drupal_check_memory_limit() and parse_size() functionality to components.

Issue #735154 by jhodgdon, pwolanin: Fixed search_touch_node()/search_mark_for_reindex() should not update if already touched.

Issue #2262975 by Berdir: Fixed Non-Multiple field types with per-field storage are not supported in CckFieldValues.

Issue #1524550 by superspring, joachim, David Hernández, marthinal, socketwench, subson | jfinkel: Fixed queue cron workers can't signal a broken queue.

Issue #1987726 by vijaycs85, disasm, YesCT, pdrake, tstoeckler, dawehner, Xano, likin, stella, andypost, prateek479, Gábor Hojtsy, kgoel: Convert language content page related callback to new style controller.

Issue #2165475 by damiankloip, dawehner, martin107, tim.plunkett, jibran, xjm, Jalandhar: Provide a generic class resolver.

Broke HEAD. Temporary rollback.

This reverts commit 5a3ef306.

Issue #2141221 by thedavidmeister, joachim, anemes: Add docs to hook_update_N to explain the sandbox usage

Issue #2246657 by tstoeckler, YesCT: $options is misnamed in Language::__construct() should be property values.

Issue #1289536 by ParisLiakos, RobLoach, Crell, larowlan, fgm, pounard, Pancho, dawehner, scor, tim.plunkett, alexpott, socketwench: Switch Watchdog to a PSR-3 logging framework.

Issue #2272081 by Wim Leers: BlockAccessController::checkAccess() should run the block plugin's access check last.