Issue #3204220 by longwave, catch: ModuleDependencyMessageTrait is used by core but belongs to system module

Issue #3205344 by alexpott: Calling system_requirements() can be expensive - do the cheap check first

Issue #3123537 by tedbow, dww, DamienMcKenna, xjm, Berdir, tim.plunkett, pingwin4eg: /admin/reports/status should not WSOD if it finds an extension missing core_version_requirement in its info.yml file

Issue #474684 by bnjmnm, dawehner, tedbow, pfrenssen, JohnAlbin, ademarco, kalpaitch, vdacosta@voidtek.com, rensingh99, markcarver, jungle, jhedstrom, RobLoach, almaudoh, kevineinarsson, shaal, dpagini, thedavidmeister, sreynen, Snugug, Miguel.kode, kamkejj, alexpott, Pol, sun, Wim Leers, lauriii, tim.plunkett, eaton: Allow themes to declare dependencies on modules

Issue #3084069 by Wim Leers, kamalzairig, zrpnr, tinko, webchick, lauriii, tedbow, ckrina: Allow marking themes as experimental

Issue #2587119 by alexpott, Jaesin, malaynayak, netw3rker, Wim Leers: Form sets system.theme:admin to '0' breaking Quick Edit and making no sense

Issue #2313917 by tedbow, pwolanin, jhedstrom, Wim Leers, Mixologic, larowlan, Mile23, Gábor Hojtsy, xjm, Berdir: Core version key in module's .info.yml doesn't respect core semantic versioning

Issue #2937853 by idebr, mfernea, SherFengChong, alexpott, borisson_: Fix 'Drupal.Formatting.MultipleStatementAlignment' coding standard

Issue #2935256 by Jo Fitzgerald, voleger, kim.pepper, ibustos, Yogesh Pawar, catch, jibran: Remove all usages of drupal_get_message and drupal_set_message in modules

Issue #2776975 by joelpittet, dawehner, tim.plunkett, xjm, pfrenssen: March 3, 2017: Convert core to array syntax coding standards for Drupal 8.3.x RC phase

Issue #2389335 by Berdir, naveenvalecha, claudiu.cristea, almaudoh, joachim, jibran: Deprecate entity.query service and replace with using the entity storage's getQuery() method

Issue #2667242 by Anul, felribeiro, eojthebrave, pranavbabbar: Use consistent terminology when referencing administration themes in the UI (not "admin theme")

Issue #2665992 by alexpott, klausi, heykarthikwithu, xjm, tstoeckler: @file is not required for classes, interfaces and traits

Issue #304540 by typhonius, BrockBoland, nabiyllin, RobLoach, marcingy, ravi.khetri, jyotisankar, sudhanshug, jaredsmith, nesta_: Disable themes when theme engine or base theme aren't available

Issue #2570355 by Sutharsan, stefan.r, kgoel, josephdpurcell, joelpittet, justAChris, dawehner, pfrenssen, pwolanin, David_Rothstein, catch: Replace remaining !placeholder and @placeholder with :placeholder for URLs

Issue #2568607 by alexpott, dawehner: Replace remaining !placeholder for Non-URL HTML outputs only in Theme name stuff in SystemController

Issue #2489830 by cilefen, davidhernandez, dcmul, Adam Clarey, joshi.rohit100, rpayanm, sqndr, Cottser, lauriii: Improve theme compatibility error message

Issue #1805054 by Wim Leers, Gábor Hojtsy, effulgentsia, jibran, jessebeach, catch, dawehner, Fabianx, sun, larowlan: Cache localized, access filtered, URL resolved, and rendered menu trees

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 #2347465 by tim.plunkett, dawehner, cilefen: Convert all instances of #type link/links to convert to use routes.

Issue #2329851 by lanchez, lauriii, Jolidog | davidhernandez: Move miscellaneous system classes from preprocess to templates.

Issue #2340251 by iMiksu, alexpott, tim.plunkett, dawehner, Wim Leers: Remove most remaining url() calls.

Issue #2305707 by cilefen, pwolanin, dawehner, LinL: MenuLinkContent disabled field should be renamed to enabled and use positive logic.

Issue #2301317 by pwolanin, dawehner, Wim Leers, effulgentsia, YesCT, xjm, alexpott: MenuLinkNG part4: Conversion.

Revert "Issue #2301317 by pwolanin, effulgentsia, Wim Leers, dawehner, alexpott: MenuLinkNG part4: Conversion."

This reverts commit fd2db9cd.

Issue #2301317 by pwolanin, effulgentsia, Wim Leers, dawehner, alexpott: MenuLinkNG part4: Conversion.

Issue #2079797 by ParisLiakos, Xano, amateescu, tim.plunkett: Provide a trait for $this->t() and $this->formatPlural().

Issue #2243549 by agerson, cs_shadow | jhodgdon: Text changes needed as follow-up to Menu UI module rename.

Issue #1067408 by alexpott, Jalandhar, jessebeach, Désiré, neetu morwani, dawehner, sun: Themes do not have an installation status.