Issue #697760 by sun: Replace getInfo() in tests with native phpDoc + annotations (following PHPUnit).

Issue #2259525 by alexpott: System.action.user_add_role_action.ROLE_ID does not match any config schema.

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

Issue #2098119 by beejeebus, alexpott, chx: Replace config context system with baked-in locale support and single-event based overrides.

Issue #1998576 by beejeebus, alexpott, swentel: Make the config import process use full config trees again.

Issue #1926276 by alexpott: Fixed Two tests in Configuration group both called 'Installation functionality'.

Issue #1891516 by sun, Berdir, chx: Remove $install parameter from DrupalUnitTestBase::enableModules(), encourage to create individual schema tables only.

Issue #1831774 by damiankloip, tim.plunkett, Gábor Hojtsy, alexpott: Fixed Config import assumes that 'config_prefix' contains one dot only.

Issue #1889752 by alexpott: Fixed Remove unnecessary manifest creation in config_install_default_config().

Issue #1761040 by sun, tim.plunkett, fago, effulgentsia: Rename Storable, Entity, and Configurable to Entity, ContentEntity, and ConfigEntity.

Issue #1668820 by sun, xjm, tim.plunkett, fgm: Concept, base class, and interface for configurable objects.

Issue #1609760 by chx, sun: Fixed hook_image_style_()*() is not invoked for image styles upon Image module installation.