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

Issue #2225427 by ianthomas_uk, martin107, JeroenT, LoMo: Remove remaining uses of deprecated language functions (mostly in object oriented code)

Issue #2328293 by keopx, JeroenT, ianthomas_uk, ashutoshsngh, rpayanm, hudo, a_thakur: Remove usage of language_list()

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

Issue #2336177 by alexpott, YesCT: Fixed ConfigurableLanguage cannot be created/removed directly, integrate language_save() and language_delete().

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

Issue #2226871 by tim.plunkett: ConfirmFormInterface::getCancelRoute() should always return Drupal\Core\Url.

Issue #1981368 by tim.plunkett, Crell, webchick: Convert all routes to 'module_name().foo_bar()' naming convention.

Issue #1963394 by tim.plunkett, jibran, effulgentsia: Fixed ConfirmFormBase::getCancelPath() should allow for a route.

Issue #1946426 by ramlev, pfrenssen, foopang, webflo, David Hernández, vijaycs85, tim.plunkett, disasm | mtift: Convert all of confirm_form() in language.admin.inc to the new form interface.

Issue #1946426 by ramlev, pfrenssen, foopang, webflo, David Hernández, vijaycs85, disasm, tim.plunkett: Convert all of confirm_form() in language.admin.inc to the new form interface.