Issue #2303673 by dawehner, damiankloip, effulgentsia, Fabianx: Implement stackphp; cleanup handlePageCache() and preHandle()

Issue #2320037 by Gábor Hojtsy: Fixed Non-fieldable entities (with only base fields) cannot be configured translatable, eg. shortcuts.

Revert "Issue #2154775 by er.pushpinderrana, barnettech, kirkkala, InternetDevels | Wim Leers: Fixed In-place editing of title: works, but cursor is invisible."

This reverts commit 3973634d.

Issue #2326949 by plach, effulgentsia: Move entity-type-specific schema information from the storage class to a schema handler.

Issue #2330503 by pfrenssen, dawehner: Fixed [sechole] Inline templates pass through unsafe strings.

Issue #2248767 by effulgentsia, beejeebus, alexpott: Use fast, local cache back-end (APCu, if available) for low-write caches (bootstrap, discovery, and config).

Issue #2202185 by Wim Leers, effulgentsia, msonnabaum, damiankloip, alexpott: Statically cache Role entities to speed up (User|UserSession)::hasPermission().

Issue #2246679 by YesCT, alimac, Michelle, martin107, eugenesia: Make Language module's LanguageInterface (to be ConfigurableLanguageInterface) extend Core's LanguageInterface.

Issue #2037979 by Gábor Hojtsy, Sweetchuck, jhodgdon, dawehner: Fixed 'Current user's language' views filter label is named very misleading.

Issue #2273277 by Wim Leers, effulgentsia, Fabianx: Fixed Figure out a solution for the problematic interaction between the render system and the theme system when using #pre_render.

Issue #2326719 by plach, effulgentsia: Move pseudo-private table mapping functions from ContentEntityDatabaseStorage to public API of DefaultTableMapping.

Issue #2224761 by Gábor Hojtsy, alexpott, pfrenssen, effulgentsia, xjm, mlncn: Add a generic way to add third party configuration on configuration entities and implement for field configuration.

Issue #2188675 by Gábor Hojtsy, marthinal, fran seva, robertdbailey, Jalandhar, vijaycs85, dlu, kfritsche, YesCT, pfrenssen: Fixed Translate local task always visible, leads to WSOD.

Issue #2270323 by sun, dawehner, neclimdul: Remove DRUPAL_ROOT constant redefinitions from unit tests.

Issue #2318429 by janoka: Fixed Language condition / block language visibility includes useless options.

Issue #1842362 by vijaycs85, Sutharsan, Berdir, ocsilalala, skipyT: Replace locale_project table and improve caching.

Issue #2310415 by cilefen, ednawig, TravisCarden: Fixed run-tests.sh does not handle the error when invalid test groups/classes are specified.

Issue #2329009 by znerol: Fixed SummaryLengthTest::testSummaryLength() must not alter WebTestBase::loggedInUser.

Issue #1974048 by Gábor Hojtsy, vijaycs85, er.pushpinderrana, Sutharsan, penyaskito, bserem: Fixed Limited display of languages when going back in installer is confusing.

Issue #2121713 by tim.plunkett, dawehner, rteijeiro, jiv_e: Move drupal_html_id() and drupal_html_class() to Drupal\Component\Utility.