Issue #2478443 by Wim Leers: Set the 'is-active' class for anonymous users in a Response Filter instead of a #post_render_cache callback

Issue #2031641 by aburrows, lauriii, nlisgo, Pol, redsquid, tuutti, LewisNyman, akalata, agviu, kallehauge, _nolocation, rpayanm, saki007ster, mdrummond, RavindraSingh, brahmjeet789: Change active class to is-active

Issue #2403301 by lokapujya, penyaskito, Wim Leers: Menu item "active" class is not correctly added when using a view as the frontpage

Issue #2412241 by idebr, Wim Leers: Active menu links with identical paths get a duplicate "active" class for every active menu link

Issue #2260121 by sun: PHPUnit Tests namespace of modules is ambiguous with regular runtime namespace (+ Simpletest tests).

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

Issue #2080343 by connork, izus, rahul.shinde, lokapujya | mrsinguyen: Remove Unused local variables from system module.

Issue #2208609 by sun, Jalandhar, damiankloip: Move Json utility class into Drupal\Component\Serialization.

Issue #2219457 by Wim Leers: SystemControllerTest::setLinkActiveClass() unit test has wrong namespace and lives in wrong location.

Issue #1979468 by Wim Leers, nod_, pwolanin, longwave, thedavidmeister, jessebeach, larowlan | catch: .active from linkGenerator(), l() and theme_links() forces an upper limit of per-page caching for all content containing links.