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 #2498691 by cilefen, mesch, deepakaryan1988, RavindraSingh, honzakuchar, darol100, kattekrab, Cottser, David_Rothstein: "Install and set as default" link on the Appearance page doesn't work

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

Issue #2470807 by LewisNyman, Dom., davidhernandez, emma.maria, lauriii, jp.stacey: Rename the default "Messages" region for all themes to "Highlighted"

Issue #2465887 by dawehner, amateescu, tim.plunkett: Extract the install/uninstall functionality to a ThemeInstaller

Revert "Issue #2470807 by LewisNyman, Dom., davidhernandez, emma.maria, jp.stacey, lauriii: Rename the default "Messages" region for all themes to "Highlighted""

This reverts commit 249e520b.

Issue #2470807 by LewisNyman, Dom., davidhernandez, emma.maria, jp.stacey, lauriii: Rename the default "Messages" region for all themes to "Highlighted"

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 #2432791 by alexpott, vijaycs85, tim.plunkett, joshtaylor, Fabianx, Berdir, yched, bojanz: Skip Config::save schema validation of config data for trusted data.

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

Issue #2090115 by alexpott, xjm: Don't install a module when its default configuration has unmet dependencies

Issue #356399 by dawehner, beejeebus, catch, sidharrell, klausi, nlisgo, Josh Waihi, Berdir, martin107: Optimize the route rebuilding process to rebuild on write

Issue #2289917 by Wim Leers, mdrummond, lauriii, Manuel Garcia, emma.maria, Scionar, davidhernandez: Convert "messages" page element into blocks

Issue #2306407 by lauriii, penyaskito, mortendk, pakmanlh, Wim Leers, ypogue: Remove breadcrumb from page template

Issue #2140511 by alexpott, Gábor Hojtsy, swentel, babruix, ohthehugemanatee, jessebeach, Berdir: Configuration file name collisions silently ignored for default configuration

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

git commit -m 'Issue #2377397 by Wim Leers, alexpott: Themes should use libraries, not individual stylesheets'

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

Issue #1869476 by rteijeiro, LewisNyman, lauriii, Wim Leers, mdrummond, swentel, hosef, cbiggins, larowlan, sun, EclipseGc, Gábor Hojtsy: Convert global menus (primary links, secondary links) into blocks.

Issue #2340123 by Wim Leers: Setting cache tags can be tricky: use strings instead of nested arrays to improve DX.

Issue #2329795 by fietserwin, bzitzow, alexrayu, tstoeckler | illutek, dawehner: Fixed Make it possible to add information to theme info files during development.

Issue #2271529 by attiks, alexpott, Lowell, YesCT, Jelle_S | mdrummond: Move breakpoint settings to theme and module *.breakpoints.yml files at root level.

Issue #2271251 by ParisLiakos, undertext, JeroenT, StevenPatz, tim.plunkett: Remove usages of watchdog() from non-form and non-controllers.

Issue #2307419 by Wim Leers: AssetCollectionOptimizerInterface should allow listing and deleting all aggregates (optimized collection assets).

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

Issue #1808248 by alexpott, beejeebus, tayzlor, Nitesh Sethia: Add a separate module install/uninstall step to the config import process.

Issue #2228921 by sun: Consolidate system.module + system.theme + system.theme.disabled into core.extension config.

Revert "Issue #1813186 by nod_: Integrate scripts/stylesheets from info/layout files with libraries."

This reverts commit 9a8caf44.

Issue #2011128 by jsbalsera, aboros, Devin Carlson, mr.baileys, pplantinga: Theme_disable() can disable the wrong theme.

Issue #340723 by ParisLiakos, sun, Berdir, glennpratt, Cottser, swentel, alexpott, tstoeckler, Xano, tim.plunkett, BassistJimmyJam | beejeebus: Make modules and installation profiles only require .info.yml files.

Revert "Issue #340723 by ParisLiakos, sun, Berdir, glennpratt, Cottser, swentel, tstoeckler, Xano, tim.plunkett, BassistJimmyJam: Make modules and installation profiles only require .info.yml files."

This reverts commit b4c561d0.