Issue #2754217 by alexpott, xjm, martin107, dawehner: Random Test Failure with "failed to open stream" for temporary://.htaccess

Issue #2783749 by alexpott, bircher: [regression] Config directories should be created by installer if present in setings.php and if possible

(cherry picked from commit 9e2f220d)

Issue #2466197 by alexpott, heddn, dawehner, pjcdawkins: Staging directory should not have to be writeable

Issue #2716685 by Mile23: Part 2: Fix several errors in the 'Drupal.Commenting.DocComment' coding standard

Issue #2572693 by Mile23, andriyun, andypost, attiks: Fix 'Drupal.ControlStructures.ControlSignature' coding standard

Issue #2700661 by anoopjohn: Ensure core compliance to Drupal.Commenting.FunctionComment.ParamCommentIndentation (part 1).

Issue #2662552 by alexpott, dawehner, xjm, catch: Early use of render service in installer is problematic

Issue #2572643 by alexpott, attiks, Jelle_S, jhodgdon: Fix Drupal.Commenting.FileComment coding standard

Issue #1386394 by David_Rothstein, Kristen Pol, tstoeckler: Add back the ability for install profiles (or at least distros) to pre-select a language or modify the language-selection screen

Issue #2487588 by YesCT, Leksat, Schnitzel, alexpott, anavarre, xjm: Move CMI import/export directory "staging" to "sync", as it is confused with staging environments

Issue #2576037 by unqunq, er.manojsharma, sdstyles, martins.kajins, Devaraj johnson, cilefen, Bojhan, Wim Leers: "Sorry" in user-facing errors violates the User Interface Standards

Issue #2543580 by harjotsingh, xq1003, kjay, longwave, jhodgdon, webchick: Post-install message referrs to "handbook" and links to irrelevant page

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 #2571375 by alexpott, webflo, stefan.r, Xano, mr.baileys: Remove TranslationManager dependency from LanguageManager

Issue #2113955 by Sutharsan, japerry, Gábor Hojtsy, basic: Rely on proper server side version fallback for translations

Issue #2487592 by alexpott, JeroenT, Schnitzel, cilefen: CMI: don't ship with a default "active" directory that is empty in most Drupal installations

Issue #2542748 by plach, effulgentsia, jhedstrom, Gábor Hojtsy, alexpott, mpdonadio, catch, dawehner: Automatic entity updates can fail when there is existing content, leaving the site's schema in an unpredictable state

Issue #2501835 by kgoel, crowdcg, stefan.r, alexpott, joelpittet, Cottser, akalata, xjm, davidhernandez, YesCT: Remove SafeMarkup::set in Drupal\Core\Database\Install\Tasks::runTasks() and ensure multiple messages are printed

Issue #2535082 by alexpott, jhedstrom, xjm, plach, Fabianx, effulgentsia, Berdir: Allow hook_update_N() implementations to run before the automated entity updates

Issue #2407195 by Wim Leers, Fabianx, joelpittet, lauriii, Crell: Move attachment processing to services and per-type response subclasses

Issue #2384675 by sidharrell, cilefen, Mile23, damiankloip, dawehner, Wim Leers, alexpott, neclimdul: Deprecate conf_path()

Issue #2491155 by mikeburrelljr, Mac_Weber, opdavies: Update drupal.org and kernel.org URLs in core modules (Follow-up to 2489912)

Issue #1081266 by stefan.r, mikeytown2, jeroen.b, tsphethean, mfb, joseph.olstad, marcelovani: Avoid re-scanning module directory when a filename or a module is missing

Issue #2322195 by rpayanm, nlisgo, cilefen, balagan, LinL, akashjain132, filijonka, epari.siva, Tebro, Temoor, pcambra, unstatu, Poornima3, Shivam Agarwal, abhi170893, Dom., PieterJanPut, Mile23, JeroenT, disasm: Replace all instances of user_load(), user_load_multiple(), entity_load('user') and entity_load_multiple('user') with static method calls

Issue #2228393 by almaudoh, andypost, pfrenssen, znerol, cpj, Dom.: Decouple session from cookie based user authentication

Issue #2232861 by grom358, daffie, alexpott, larowlan, pfrenssen, hussainweb, pcambra, jibran, phenaproxima, moshe weitzman, nick_schuch: Create BrowserTestBase for web-testing on top of Mink

Issue #2451363 by alexpott, Berdir, pjcdawkins: Ensure install_profile is exists in settings.php after installation