Issue #2426031 by almaudoh, cpj: Remove deprecated uses of SessionManager::isEnabled(), SessionManager::enable() and SessionManager::disable()

Issue #2382195 by tibbsa, subhojit777, tadityar, cilefen, Mile23: Clean-up simpletest module test members - ensure property definition and use of camelCase naming convention

Issue #2395395 by alexpott, effulgentsia, Gábor Hojtsy: TestBase lacks a config method to be used consistently in tests

Issue #287292 by almaudoh, mr.baileys, drewish, Berdir, znerol, boombatower, dawehner, jpetso, floretan: Add functionality to impersonate a user

Issue #2294571 by znerol, effulgentsia: Redirect anonymous users to login page from an exception listener instead of in MaintenanceModeSubscriber and restrict access to the my-account link to authenticated users.

Issue #2330279 by znerol: Fixed When operating in mixed mode SSL: data from anonymous non-HTTP session is still available after login.

Issue #1498664 by andypost, plach, penyaskito | dawehner: Refactor user entity properties to multilingual.

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

Issue #697760 by sun: Replace getInfo() in tests with native phpDoc + annotations (following PHPUnit).

Issue #2239969 by znerol, alexpott, neclimdul, sun: Fixed session of (UI) test runner leaks into web tests.