Issue #2012812 by thedavidmeister, pwieck: drupal_render() can't distinguish between empty strings from theme() from an implemented hook and no hook being matched.

Issue #2022087 followup by damiankloip: Add module owner to plugin definition in AnnotatedClassDiscovery.

Issue #1828536 by sun, thedavidmeister, benjf, derek.deraps, jenlampton, dcam, pwieck: Rename 'type' variable of theme_item_list() to 'list_type'.

Issue #1987822 by vijaycs85, jrglasgow, tim.plunkett: Convert system_date_time_lookup() to a new style controller.

Issue #1858616 by Berdir: Extract generic CacheCollector implementation and interface from CacheArray.

Issue #2013094 by pwieck, Cottser: Remove unnecessary template_preprocess() reference from all Twig files

Issue #2004350 by Berdir, Dean Reilly: Fixed Unserialised database connection objects don't use Drupal's PDO Statement class.

Issue #1965208 by amateescu, Berdir: Convert TaxonomyTermReferenceItem to extend EntityReferenceItem.

Issue #1668866 by ParisLiakos, aspilicious, tim.plunkett, pdrake, g.oechsler, dawehner, Berdir, corvus_ch, damiankloip, disasm, marcingy, neclimdul: Replace drupal_goto() with RedirectResponse.

Issue #1852454 by patrickd, xjm, YesCT, Berdir, amateescu, Pancho, djroshi, dealancer, Wim Leers, jessebeach: Restrict module and theme name lengths to 50 characters.

Issue #1777956 by fago, klausi, sun, dasjo: Provide a way to define default values for entity fields.

Issue #1983548 by Berdir, LukyLuke_ch, giammi, effulgentsia: Convert contact message entities to the new Entity Field API.

Issue #1939066 by joelpittet, chrisjlee, Cottser, splatio, jenlampton: Convert theme_breadcrumb() to Twig.

Issue #1981342 by aspilicious, andypost, swentel: Drop procedural usage of fields in [s-u-v] modules.

Issue #1998698 by larowlan, jibran, quicksketch: Allow Dialog Controller to work with form/entity form routes.

Issue #1947536 by andypost, donquixote, larowlan, splatio, kim.pepper, alexpott, Crell, tim.plunkett: Convert drupal_get_breadcrumb() and drupal_set_breadcrumb() to a service.

Issue #1982980 by ParisLiakos, larowlan, dawehner, tim.plunkett: Move entity_get_form() to Drupal\Core\Entity\EntityManager::getForm().

Issue #1939090 by 2ndmile, hefox, Cottser, shanethehat, steveoliver, jenlampton, mr.baileys, derheap: Convert theme_tablesort_indicator() to Twig.

Issue #2003366 by sillygwailo, Joe9, kenianbei, pcambra, heddn, YesCT, damiankloip: Rename Views method pre_render() to preRender().

Issue #1363112 by mparker17, mgifford, tlattimore, Jacine, dcmouyard, bowersox, ry5n, ahdiaz: Simplify names of 'element-x' helper classes.

Issue #1903346 by Berdir, tim.plunkett, EclipseGc: Establish a new DefaultPluginManager to encapsulate best practices.

Issue #2012682 by fago: Fixed Constraints in getPropertyDefinitions generate violations without a delta.

Issue #2008558 by effulgentsia: Move nonalterations from hook_entity_bundle_info_alter() implementations to hook_entity_bundle_info() implementations.

Issue #1893772 by chx, fubhy, slashrsm: Move entity-type specific storage logic into entity classes.

Issue #2003568 by dawehner, jhedstrom: Convert tags,attributes, diff and url validation unit tests to phpunit.