Issue #1494670 by Liam Morland, jhedstrom, Wim Leers, mfb: References to CSS, JS, and similar files should be root-relative URLs: avoids mixed content warnings & fewer bytes to send

Issue #2571845 by drupal.ninja03, hussainweb, anil280988, snehi, jhodgdon, GoZ, stefan.r: Links to wikipedia/php.net should be part of the actual t() string so they can be localized

Issue #2619332 by joelpittet, jmarkel, Wim Leers, Berdir, chintan.vyas, netsensei: Color scheme config changes aren't reflected in cached pages

Issue #2493475 by ifrik, walangitan, XaviP, jhodgdon, batigolix: Fix online docs references in Help to conform to our standards

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 #2560783 by stefan.r, joelpittet, lauriii, Cottser, Sutharsan, kgoel, justAChris, Gábor Hojtsy, dawehner, jhodgdon, effulgentsia, xjm, andypost, googletorp: Replace !placeholder with :placeholder for URLs in hook_help() implementations

Issue #2005546 by mdrummond, joelpittet, Manuel Garcia, lauriii, lokapujya, epari.siva, hosef, rpayanm, emma.maria, HOG, zetagraph, wmortada, rteijeiro, Cottser, hussainweb, madhavvyas: Use branding block in place of page template branding variables (site name, slogan, site logo)

Issue #2548991 by Wim Leers, Mile23: Remove Bartik's erroneous use of drupal_process_attached(), add tests

Issue #2560641 by alexpott, lauriii, Xano, borisson_, ianthomas_uk, olli: Remove all usages SafeMarkup::checkPlain() from render arrays

Revert "Issue #2560641 by alexpott, lauriii, Xano, borisson_, ianthomas_uk: Remove all usages SafeMarkup::checkPlain() from render arrays"

This reverts commit 31007609.

Issue #2560641 by alexpott, lauriii, Xano, borisson_, ianthomas_uk: Remove all usages SafeMarkup::checkPlain() from render arrays

Issue #2501701 by akalata, pwolanin, lauriii, GreenSkunk, cdulude, joelpittet, Cottser: Remove SafeMarkup::set in template_preprocess_color_scheme_form()

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

Issue #2457887 by prateekMehta, stefan.r, rpayanm, alexpott: Use Utility\SafeMarkup class instead of Utility\String for placeholder(), checkPlain(),format() functions

Issue #2142653 by corbacho, sqndr, LewisNyman, floretan, BarisW, G-raph, JamesLefrère, lokapujya, LoMo, Outi: Change default logo filetype to .svg and add an SVG version of Druplicon

Issue #2392319 by alexpott, effulgentsia: Config objects (but not config entities) should by default be immutable

Issue #2391245 by Gábor Hojtsy, Wim Leers: Resolve remaining misc issues with configuration schema fails

Issue #2378095 by Wim Leers, Devin Carlson: Convert all remaining attached individual CSS/JS assets to attached asset libraries

Issue #2328111 by dawehner, martin107, neclimdul: Replace most instances of the DRUPAL_ROOT constant with the app.root container parameter.

Issue #2246675 by rpayanm, johnstorey, holly.ross.drupal | mgbellaire: Remove all unnecessary 'template' lines in hook_theme() declarations.

Issue #2228745 by Wim Leers, sqndr, nod_, undertext: Fixed Color module doesn't look for CSS files declared in a library.

Issue #2335659 by tim.plunkett, dawehner, effulgentsia, sun: Remove FormState ArrayAccess usage from core.

Issue #1825952 by Fabianx, joelpittet, bdragon, heddn, chx, xjm, pwolanin, mikey_p, ti2m, bfr, dags, cilefen, scor, mgifford: Turn on twig autoescape by default

Issue #2003800 by jhedstrom, filijonka, YesCT, ParisLiakos, steeloctopus, damiankloip, sun, LinL, amateescu: Move drupal_check_memory_limit() and parse_size() functionality to components.

Revert "Issue #1106160 by tim.plunkett, BarisW: Fixed Color module uses the public file system but doesn't check if it is set."

This reverts commit cef318b5.