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 #1620114 by Rob Loach, sun: Explicitly register \Drupal\Component and \Drupal\Core to increase class lookup performance.

Issue #1696640 by fago, effulgentsia, tim.plunkett, dixon_, plach: Add a uniform Entity Property API.

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

Issue #1436814 by gary4gar, kid_icarus, webchick, droplet, andypost: Fixed Fast 404 'Not found' pages are missing a doctype.

Patch #1161486 by rootatwc, sun, andypost, catch, marcingy, aspilicious, cam8001: Move IP blocking into its own module.

Issue #1175054 by msonnabaum, chx, sun, tim.plunkett, arlinsandbulte, beejeebus: Add a storage (API) for persistent non-configuration state.

Issue #1772708 by alexpott, sun, chx, catch, beejeebus: Fixed The configuration directories can not be outside of DRUPAL_ROOT.

Issue #1542620 by djdevin, rootatwc: Fixed Fatal errors when file permissions for settings.php are messed up (can't read file).

Issue #1739592 by Albert Volkman, andy.hails, dawehner: Fix up docs of a few language-related functions

Revert "Issue #1772708 by alexpott: Fixed The configuration directories can not be outside of DRUPAL_ROOT."

This reverts commit e003e4c5.

Issue #1055862 by sun, catch, pillarsdotnet, danillonunes: Require sites.php to opt-in for multi-site support/functionality.

Issue #1741804 by beejeebus, sun, chx, alexpott, matason: Implement a config import/staging directory.

Issue #1669902 by alexpott, aspilicious, sun: Adjust system.performance configuration for new guidelines.

Issue #1675260 by chx, effulgentsia, pwolanin, neclimdul: Implement PHP reading/writing secured against 'leaky' script.

Issue #1646580 by chx, Jose Reyero, beejeebus: Implement Config Events and Listeners, and storage realms for localized configuration.

Issue #1018324 by Albert Volkman, webbykat, disasm,  jhr, jorap: Add info and examples to docs on how to set up multi-site

Issue #562042 by cburschka, Rob Loach, sun, scor: Added Search for install profiles in sites/[all|site]/profiles folders, and move core profiles into /core/profiles.

- Patch #1671080 by sun, no_commit_credit, Gábor Hojtsy, Jose Reyero: remove StorageDispatcher to simplify configuration system.