Issue #1331486 by katbailey, chx, sun, beejeebus, amateescu: Move module_invoke_*() and friends to an Extensions class.

Issue #1778178 by fago, Berdir, effulgentsia, mradcliffe, das-peter: Convert comments to the new Entity Field API.

Issue #1833516 by Berdir, chx, catch, webchick: Add $settings for low-level configuration - move things out of .

Issue #1814086 by samhassell, fgm: Convert autoloader_mode in drupal_classloader() to its own global.

Issue #1158322 follow-up by chx: Fixed htmlspecialchars() expects parameter 1 to be string, array given errors in exception backtraces.

Issue #1873608 by David_Rothstein: Improve documentation of format_string() to emphasize that it is used to prepare variables for HTML display.

Issue #1861604 by hefox: Skip module_invoke()/module_hook() in calling hook_watchdog() (excessive function_exist()).

Issue #1705920 by tim.plunkett, sun, underq, javier.alejandr...: Convert all calls to procedural drupal_array_()*() functions to Drupal\Component\Utility\NestedArray.

Issue #1187726 by chx, Berdir, Fabianx, sun: Fixed Add caching for configuration / rework config object loading.

Issue #1834594 by effulgentsia, Rob Loach: Update dependencies (Symfony and Twig) follow up fixes for Composer.

Revert "Revert the revert of Issue #1849004 by chx, xjm: One Service Container To Rule Them All. It was innocent after all."

This reverts commit a1638b87.

This reverts commit 761ac679.

Issue #1571632 by cosmicdreams, marcingy, justafish, chx, KarenS, aspilicious, disasm, swentel, dawehner, rvilar: Convert regional settings to configuration system.

Issue #1848072 by katbailey, sun: Fixed Path alias manager hardcodes keyvalue.database instead of using the generic factory.

- Issue #1739986 by pwolanin, sun, moshe weitzman: Fixed fallback in drupal_get_hash_salt(), move it to bootstrap.inc, use instead of ['drupal_hash_salt()'].

Issue #1269742 by katbailey, beejeebus, pwolanin, g.oechsler, ksenzee: Make path lookup code into an pluggable class.

Issue #1739986 by pwolanin, moshe weitzman: Fixed fallback in drupal_get_hash_salt(), move it to bootstrap.inc, use instead of $GLOBALS['drupal_hash_salt()'].

Issue #1808200 by sun: Fixed Unit test performance significantly decreased since system list config conversion.