Issue #2873696 by nvexler, wengerk, gido, Jo Fitzgerald, xjm: Add @internal to core classes, methods, properties to Form Classes

Issue #2776975 by joelpittet, dawehner, tim.plunkett, xjm, pfrenssen: March 3, 2017: Convert core to array syntax coding standards for Drupal 8.3.x RC phase

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

Issue #2453175 by tim.plunkett, plach, rteijeiro, effulgentsia, eshta, dawehner, fago, Berdir, alexpott: Remove EntityFormInterface::validate() and stop using button-level validation by default in entity forms

Issue #1392754 by tss, justAChris, jhodgdon: Comply with new documentation standards for @file for namespaced class files

Issue #2230637 by plach, fran seva, yched, swentel: Create a Language field widget and the related formatter

Issue #2340667 by YesCT, Pedro Lozano, alexpott, martin107: Protect Drupal\Core\Language\Language::id, and use getId().

Issue #2335659 by tim.plunkett, dawehner, effulgentsia, sun: Remove FormState ArrayAccess usage from core.

This reverts commit 3ac426f9.

Issue #2022875 by Berdir, alexpott, Xano, swentel, tim.plunkett, vladan.me: Resolve difference between submitForm(), submit(), and save() in EntityFormController.

Issue #2246665 by jaredsmith, martin107, YesCT, filijonka, tstoeckler: Typehint with Drupal\Core\Language\LanguageInterface instead Drupal\Core\Language\Language.

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 #2165155 by Berdir, tim.plunkett: Change $entity_type to $entity_type_id and $entity_info to $entity_type/$entity_types.

Issue #2164827 by Berdir, Xano, tim.plunkett: Rename the entityInfo() and entityType() methods on EntityInterface and EntityStorageControllerInterface.

Issue #2005716 by tim.plunkett, msonnabaum, dawehner, alexpott, effulgentsia: Promote EntityType to a domain object.

Issue #2004244 by Berdir, plach, tim.plunkett, msonnabaum, das-peter: Move entity revision, content translation, validation and field methods to ContentEntityInterface.

Issue #1810370 by plach, kfritsche, berdir, alexpott, xjm, chx: Entity Translation API improvements.

Issue #1754246 by webflo, swentel, penyaskito, andypost, alexpott, YesCT, dagmar: Languages should be configuration entities.

Issue #2004224 by Berdir, andypost: Convert tests using TestEntity to EntityTest (except Field API tests).

Issue #1620010 by dawehner, ParisLiakos, plach, jibran: Move LANGUAGE constants to the Language class.

Issue #1913618 by tim.plunkett, amateescu: Convert EntityFormControllerInterface to extend FormInterface.

Issue #1801304 by Amitaibu, amateescu, effulgentsia, tim.plunkett, EclipseGc, Fabianx, Cottser: Added Entity reference field.

Issue #1833334 by das-peter, plach, Berdir, fago: EntityNG: integrate a dynamic property data table handling.

Issue #1188388 by plach, peximo, YesCT | Gábor Hojtsy, fago, webchick, Bojhan, podarok, cosmicdreams, Berdir, aspilicious, bforchhammer, penyaskito: Added Entity translation UI in core.

Issue #1696640 by fago, effulgentsia, tim.plunkett, dixon_, plach: Add a uniform Entity Property API.