Issue #2166065 by alexpott, mtift: Replace config_install_default_config with ConfigInstaller service.

Issue #2133325 by mtift, alexpott, sun: Create a site UUID on install and only allow config sync between sites with the same UUID.

Issue #1954892 by dawehner, David_Rothstein, tim.plunkett: Replace 'theme callback' and hook_custom_theme() with a clean theme negotiation system.

Issue #1998638 by damiankloip, dawehner, kim.pepper, cosmicdreams, alexpott, larowlan, Damien Tournoud: Replace almost all remaining superglobals (, , etc.) with Symfony Request object.

Issue #1998638 by damiankloip, dawehner, kim.pepper, cosmicdreams, larowlan, Damien Tournoud: Replace all remaining superglobals (, , etc.) with Symfony Request object.

Issue #2102417 by damiankloip, dawehner: Change Drupal\Core\Routing\RouteBuildEvent::getModule() to getProvider().

Revert "Issue #1954892 by dawehner, tim.plunkett, David_Rothstein, effulgentsia: Replace 'theme callback' and hook_custom_theme() with a clean theme negotiation system."

This reverts commit fc04601c.

Issue #1954892 by dawehner, tim.plunkett, David_Rothstein, effulgentsia: Replace 'theme callback' and hook_custom_theme() with a clean theme negotiation system.

Issue #2045931 by PerthSam152, LinL, adsw12, joelpittet: Replace all module_exists() deprecated function calls.

This reverts commit cc84f390 - bad
commit message.

Issue #2089327 by thedavidmeister, Cyberschorsch: Remove / deprecate calls to drupal_strip_dangerous_protocols() use \Drupal\Component\Utility\Url::stripDangerousProtocols().

Issue #2099467 by moshe weitzman, chx: Let non-interactive installers determine mode of files directory and its subdirectories.

Issue #2080071 by rhm50: Remove Unused local variable $base_url() from /core/modules/system/system.install.

Issue #1798738 by alexpott, mtift, tayzlor, ianmthomasuk, Albert Volkman, heyrocker, cam8001: Move css_js_query_string() to state system.

Issue #2009674 by pplantinga, Samvel, dmitrii: Replace theme() with drupal_render() in system module.

Issue #1969572 by neclimdul, larowlan, hussainweb, dawehner, damiankloip, ParisLiakos, pwieck, Berdir, socketwench: Make Uuid a service.

Issue #1199946 by alexpott, fubhy, bojanz, steinmb, chx, catch: Fixed Disabled modules are broken beyond repair so the 'disable' functionality needs to be removed.

Issue #2051097 by dawehner, Manuel Garcia, tlattimore, neclimdul: Change 'pattern' to 'path' in *.routing.yml files.

Issue #2084339 by alexpott: Fixed The configuration value system.maintenance.enabled should be moved to the state system.

Issue #2082499 by alexpott: Fixed Uninstalling action module removes actions created by the user module.

Issue #1856766 by chx, Berdir, heyrocker, kim.pepper: Convert file_public_path() to the new settings system (make it not configurable via UI or YAML).

Issue #2062127 by jlindsey15, joachim: Document system_requirements as implementation of hook_requirements

Issue #1934712 by dlu, alexpott, pplantinga, rbayliss, s_leu, Gaelan: Fixed Merge system.timezone config object into system.date.

Issue #1998204 by tim.plunkett: Fixed config_install_default_config() is not safe to use in hook_update_N().

Issue #2029321 by tim.plunkett, aspilicious, swentel: Provide list and form controllers for EntityViewMode and EntityFormMode.

Issue #1833022 by e0ipso, plach, YesCT, kfritsche, penyaskito, vijaycs85, nod_, cam8001: Only display interface language detection options to customize more granularity.

Issue #1872876 by chx, fubhy, dawehner, alexpott, tim.plunkett: Turn role permission assignments into configuration.