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.

Issue #1706064 by chx, katbailey, effulgentsia, podarok et al: Compile the Injection Container to disk.

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.