Issue #2699613 by alexpott, catch, Wim Leers, Berdir, dawehner, mpdonadio, borisson_, Fabianx: Set a shorter TTL for 404 responses in page_cache module

Issue #2665992 by alexpott, klausi, heykarthikwithu, xjm, tstoeckler: @file is not required for classes, interfaces and traits

Issue #2527126 by Wim Leers, dawehner, effulgentsia, anavarre, janusman, Fabianx, alexpott, hass, catch, Berdir, znerol: Only send X-Drupal-Cache-Tags and -Contexts headers when developer explicitly enables them

Issue #2476407 by borisson_, hussainweb, znerol, Fabianx, Wim Leers, dawehner, Crell, Berdir: Use CacheableResponseInterface to determine which responses should be cached

Issue #2493033 by Berdir, Wim Leers, lauriii, Fabianx, effulgentsia, dawehner, catch, msonnabaum, Crell, webchick: Make 'user.permissions' a required cache context

Issue #2421503 by lauriii, larowlan, Wim Leers, dawehner, tim.plunkett: SA-CORE-2014-002 forward port only checks internal cache

Issue #2509300 by dawehner, catch, larowlan: Path alias UI allows node/1 and /node/1 as system path then fatals

Issue #2481453 by dawehner, pwolanin, rteijeiro, neclimdul, znerol: Implement query parameter based content negotiation as alternative to extensions

Issue #2368987 by Wim Leers, Berdir, Schnitzel, epari.siva, bircher, vijaycs85, likin: Move internal page caching to a module to avoid relying on config get on runtime

Issue #2472281 by pwolanin: 404/403 responses for non-existing nodes are cached in Page Cache/reverse proxy, are not invalidated when the node is created

Issue #2467041 by mr.baileys, jan.stoeckler: max-age on HTML responses wrongly set to `max-age=0, private` instead of `max-age=N, public` (breaks reverse proxies and client-side caching)

Issue #2464659 by Wim Leers, rteijeiro: Routes that are varied by the 'user.permissions' cache context for anonymous users must also get the anonymous Role's cache tag

Issue #2040135 by Wim Leers, Berdir: Caches dependent on simple config are only invalidated on form submissions

Issue #2395395 by alexpott, effulgentsia, Gábor Hojtsy: TestBase lacks a config method to be used consistently in tests

Issue #2350823 by lauriii, jhedstrom, Tim Bozeman, cilefen, davidhernandez, inqui, Cottser, xjm: Use the Classy theme in the Testing profile

Issue #2340251 by iMiksu, alexpott, tim.plunkett, dawehner, Wim Leers: Remove most remaining url() calls.

Issue #2340123 by Wim Leers: Setting cache tags can be tricky: use strings instead of nested arrays to improve DX.

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

Issue #2124957 by Wim Leers, catch: Replace 'content' cache tag with 'rendered' and use it sparingly.

Issue #2257709 by znerol, Wim Leers: Remove the interdependence between the internal page cache and management of the Cache-Control header for external caches.

Issue #2185617 by Wim Leers, voidberg, drifter: Each page cache entry should have a theme cache tag.

Issue #2217371 by Wim Leers: Expose cache tags to reverse proxies: X-Drupal-Cache-Tags header (by just slightly changing an existing header).

Issue #2167039 by likin, dawehner, Wim Leers, tstoeckler, vijaycs85: Regression: page cache tags broken, also: some routes incorrectly use _controller -> No page object in template variables -> Fatal in seven_preprocess_page().

Issue #1957142 follow-up by dawehner, jibran: Fix a few more config() => Drupal::config() stragglers.

Issue #1476810 by Spleshka, franz: Fixed drupal_serve_page_from_cache() can serve uncompressed data with Content-Encoding gzip header with page_cache_without_database = 1.

Issue #1855260 by beejeebus, msonnabaum, larowlan: Fixed Page caching broken by accept header-based routing.