Issue #1957154 by joates, ayelet_Cr, xjm | Berdir: Replace calls to drupal_container()->get('module_handler()') service with Drupal::moduleHandler().

Issue #2004784 by chx, effulgentsia: Move module enable/disable/uninstall implementations into ModuleHandler.

Issue #1975354 by dawehner: Fixed hook_hook_info() might be invoked even the namespace hasn't been registered yet.

Issue #1827448 by RobLoach, sun, jbrown, tstoeckler: Use __DIR__ instead of DRUPAL_ROOT where possible/sensible.

Issue #1167144 by chx, catch, claudiu.cristea: Make cache backends responsible for their own storage.

Issue #1937600 by Berdir, rootatwc | webchick: Determine what services to register in the new Drupal class.

Issue #1929656 by dawehner: Fixed ModuleHandler::setModuleList() should call resetImplementations() in order to avoid edge cases.

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

Revert "Issue #1331486 by katbailey, chx, sun, beejeebus, amateescu: Move module_invoke_*() and friends to an Extensions class. Broke core tests after commit."

This reverts commit c80c3e18.

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

Issue #1356170 by ohnobinki, tim.plunkett: Remove all uses of array_merge_recursive(), or document why they are being used instead of NestedArray::mergeDeep().

Issue #1849700 by katbailey, effulgentsia: Fixed DrupalKernel's container.modules param should contain module filenames, not full namespace paths.

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

Issue #1697256 by heyrocker, alexpott, sun, xjm, webchick: Create a UI for importing new configuration.

Issue #1830170 by fubhy: Fixed module_list() doesn't register namespaces with the classloader when given a fixed module list.

Issue #1708692 by xjm, effulgentsia, tim.plunkett, fubhy, Berdir, chx: Fixed Bundle services aren't available in the request that enables the module.

Issue #1608842 by chx, alexpott, sun, effulgentsia, beejeebus, tim.plunkett et al: Replace list of bootstrap modules, enabled modules, enabled themes, and default theme with config.

Issue #1040790 by yched, swentel, geerlingguy, beejeebus, Berdir: Fixed _field_info_collate_fields() memory usage.

Issue #1215104 by sun, lucascaro, effulgentsia: Use the non-interactive installer in WebTestBase::setUp().

Issue #1708722 by David_Rothstein, kim.pepper: Fixed Call to undefined function drupal_find_base_themes() in /includes/module.inc on line 184.