Issue #1919420 by sun: Remove datetime upgrade path check from its hook_install().
Issue #1849752 by effulgentsia, Berdir, jibran, neclimdul: Abstract non-Drupal-specific parts of AnnotatedClassDiscovery into a Drupal\Component base class.
Issue #1793074 by cweagans, sun, chx: Convert .info files to YAML.
Issue #1875182 by yched: Pass plugin definition to plugin instances instead of discovery object.
Issue #1735118 by swentel, yched, xjm, larowlan, alexpott, tim.plunkett: Convert Field API to CMI.
Issue #1969714 by yched: Fixed Stale class names for FieldInstance in phpdocs.
Issue #1971046 by ACF | Berdir: Fixed DateTimeFieldTest is DatetimeFieldTest.php (incorrect case).
Issue #1292284 by ParisLiakos, RobLoach, karschsp: Require 'type' key in .info.yml files.
Issue #1854868 by swentel: Let formatter summaries return arrays instead of strings.
Issue #1875992 by amateescu, swentel, yched: Add EntityFormDisplay objects for entity forms.
Issue #1620010 by dawehner, ParisLiakos, plach, jibran: Move LANGUAGE constants to the Language class.
Issue #2004224 by Berdir, andypost: Convert tests using TestEntity to EntityTest (except Field API tests).
Issue #1985344 by tim.plunkett, swentel: Add a dedicated @FieldFormatter annotation.
Issue #2006484 by tim.plunkett, dawehner: Remove dependency on datetime from node.
Issue #2008986 by markie: Replace theme() with drupal_render() in datetime module.
Issue #2006484 followup by amateescu: Remove dependency on datetime from node.
Issue #1950632 by effulgentsia, Wim Leers, amateescu, yched: Create a FieldDefinitionInterface, decoupled from  and  config entities, and use it for formatters and widgets.
Issue #2018731 by swentel: Move field_has_data() to Field::hasData().
Issue #1981306 by aspilicious, andypost, pcambra, swentel, amateescu: Drop procedural usage of fields in [a-e] modules.
Issue #1969728 by yched, effulgentsia, swentel, fago, plach: Implement Field API 'field types' as TypedData Plugins.