Issue #2935254 by kim.pepper: Remove all usages of drupal_get_message and drupal_set_message in core includes

Issue #2556025 by david_garcia, dawehner, -enzo-, Fabianx, catch: Make optimized class loader detection more generic to support class loaders other than ApcClassLoader

Issue #2400197 by pwolanin, fgm, znerol, neclimdul, mpdonadio, thekevinday, Fabianx: Harden the security where hash values are compared

Issue #2380389 by webflo, Mile23, davidwbarratt, timmillwood, hussainweb, tstoeckler, bojanz, yched, MKorostoff, alexpott, webchick: Use a single vendor directory in the root

Issue #2406681 by tstoeckler, hussainweb, alexpott, ParisLiakos, almaudoh, tadityar: Add an autoload.php in the repo root to control the autoloader of front controllers

Issue #2304949 by mpdonadio, cilefen, znerol, klausi, gaurav.goyal, regilero: Port HTTP Host header DoS fix from SA-CORE-2014-003

Issue #2328111 by dawehner, martin107, neclimdul: Replace most instances of the DRUPAL_ROOT constant with the app.root container parameter.

Issue #2016629 by larowlan, neclimdul, sun, alexpott, jibran, ParisLiakos, donquixote, effulgentsia, msonnabaum: Refactor bootstrap to better utilize the kernel.

Revert "Issue #2016629 by larowlan, neclimdul, sun, alexpott, jibran, ParisLiakos, donquixote, effulgentsia, msonnabaum: Refactor bootstrap to better utilize the kernel."

This reverts commit cda051c4.

Issue #2016629 by larowlan, neclimdul, sun, alexpott, jibran, ParisLiakos, donquixote, effulgentsia, msonnabaum: Refactor bootstrap to better utilize the kernel.