Issue #2286971 by znerol, Berdir, almaudoh, cilefen: Remove dependency of current_user on request and authentication manager

Issue #2229145 by znerol, neclimdul, larowlan, alexpott, joelpittet, almaudoh, tadityar: Register symfony session components in the DIC and inject the session service into the request object

Revert "Issue #2229145 by znerol, neclimdul, larowlan, joelpittet, almaudoh: Register symfony session components in the DIC and inject the session service into the request object"

This reverts commit b926f5d8.

Issue #2229145 by znerol, neclimdul, larowlan, joelpittet, almaudoh: Register symfony session components in the DIC and inject the session service into the request object

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

Issue #2303673 by dawehner, damiankloip, effulgentsia, Fabianx: Implement stackphp; cleanup handlePageCache() and preHandle()

Issue #2250243 by dawehner, sun: Remove needless ContainerAware dependency from AuthenticationManager.

Issue #2284103 by alexpott, fabpot, damiankloip, Xano, Xen, Berdir: Fixed Remove the request from the container.

Issue #2228341 by sun, znerol, skipyT, ParisLiakos: Objectify session management functions + remove session.inc.

Issue #2180109 by damiankloip, dawehner, ParisLiakos, joelpittet, MartijnBraam, Xano: Change the current_user service to a proxy.

Issue #2178581 by damiankloip, penyaskito, Solthun: Add an AnonymousUserSession object in favour of using drupal_anonymous_user().

Issue #2073531 by tim.plunkett, dawehner, Berdir, catch, plach: Use current user service instead of _account, remove _account from the request object.

Issue #2041885 by BTMash, cweagans, klausi: Move HTTP basic authentication provider to a separate module.

Issue #2052389 by pwolanin: Fixed All elements added to the Request attributes should have a _ prepended unless they come from the path.

Issue #2043781 by pwolanin: Fixed Drupal::request()->attributes->get('account') may conflict with an account object loaded from the path.

Issue #1890878 by corvus_ch, ygerasimov, berenddeboer, Crell, fubhy the cat, effulgentsia: Add modular authentication system, including Http Basic; deprecate global .