Issue #507488 by lauriii, mdrummond, Wim Leers, Manuel Garcia, pwolanin, davidhernandez, chx, jibran, andypost, dawehner, Xano, tuutti, Gábor Hojtsy, LewisNyman, maximiliam, eiriksm, borisson_, bill richardson, Fabianx, joelpittet, Jeff Burnz, xjm, webchick, Bojhan, EclipseGc, emma.maria, tim.plunkett: Convert page elements (local tasks, actions) into blocks

Issue #2489162 by googletorp, Haza, mdrummond, DuaelFr, swentel: Can configure responsive image formatter to cause fatal error

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

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

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 #2450637 by tim.plunkett, jasonawant: Block page visibility option "Show for the listed pages" does not appear to save

Issue #2407361 by cilefen, JeroenT, hussainweb, neclimdul, ircmaxell, tim.plunkett, nlisgo, Crell: Move usages of drupal_html_id() to Html::getUniqueId()

Revert "Issue #2407361 by JeroenT, cilefen, hussainweb: Move usages of drupal_html_id() to Html::getUniqueId()"

This reverts commit 85b8c837.

Issue #2407361 by JeroenT, cilefen, hussainweb: Move usages of drupal_html_id() to Html::getUniqueId()

Issue #1728804 by Berdir: Introduce (Content)EntityDeleteForm and children to handle entity deletions

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

Issue #2342057 by dawehner, hussainweb, Wim Leers: Expand BlockPluginInterface to take into account $return_as_object

Issue #2030571 by calebtr, daffie, filijonka, YesCT, Thomas Brekelmans, alexpott, Mile23, tadityar, Sharique, tim.plunkett, boztek: Expand Block with methods

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

Issue #2382543 by rpayanm, ianthomas_uk: Remove usage of drupal_html_class() and drupal_clean_css_identifier()

Issue #2263359 by jhodgdon: hook_help(): Top of page help sections can't link to help pages without a fatal error or checking for help module

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

Issue #2339151 by EclipseGc, tim.plunkett, Gábor Hojtsy, effulgentsia: Conditions / context system does not allow for multiple configurable contexts, eg. language types

Issue #2340785 by mpdonadio: Create proper test method for determining if text has been escaped properly.

Issue #2362517 by Wim Leers: Improve default 403/404 exception HTML subscriber: don't duplicate the page render pipeline, use the routing system — add system.403 and system.404 routes.

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 #2321593 by Temoor: Replace all instances of block_load(), entity_load('block') and entity_load_multiple('block') with static method calls.

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 #2278541 by tim.plunkett, kim.pepper, Bojhan, EclipseGc: Refactor block visibility to use condition plugins.

Issue #216064 by Xano, idflood, drifter, Artusamak, ygerasimov, sun, ParisLiakos, Cottser, TravisCarden, marcingy, floretan, catch, tedbow: Entity form "Delete" button triggers server-side + HTML5 form validation; change "Delete" button to a link.

Issue #214760 follow-up by sun,  lokapujya: Revised tests for theme name in block admin shows HTML entities: excessive check_plain().

Issue #214760 by Jalandhar, lokapujya, dcam, naquah: Theme name in block admin shows HTML entities: excessive check_plain().

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