Issue #2935256 by Jo Fitzgerald, voleger, kim.pepper, ibustos, Yogesh Pawar, catch, jibran: Remove all usages of drupal_get_message and drupal_set_message in modules

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

Issue #2482783 by dmsmidt, alexpott, mgifford, 20th, Sutharsan, Jo Fitzgerald, tim.plunkett, dandaman, xjm: File upload errors not set or shown correctly

Issue #2887259 by Tessa Bakker, Sutharsan: Code style issues of require_once in ImportForm::submitForm

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 #2719695 by alexpott, Mile23: Fix 'Drupal.Classes.ClassDeclaration.CloseBraceAfterBody' coding standard

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

Issue #2557113 by stefan.r, alexpott, dawehner, joelpittet, cilefen, lauriii, plach, catch, chx, xjm: Make t() return a TranslationWrapper object to remove reliance on a static, unpredictable safe list

Issue #2561259 by stefan.r, lauriii, joelpittet, andypost: Cast (optgroup) array keys that may hold translated strings to string

Issue #2212069 by Gábor Hojtsy, pjonckiere, rteijeiro, cilefen: Non-English Drupal sites get default configuration in English, edited in English, originals not actually used if translated

Issue #2095787 by Sutharsan, Gábor Hojtsy, fran seva, adci_contributor, rpayanm: Configuration translations not updated when manually importing a .po file

Issue #2341341 by YesCT, martin107, vijaycs85, fran seva: Change public 'name' property access on languages to getName() and add back setName().

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

Issue #2308821 by tim.plunkett: Replace FormErrorInterface with $form_state->setErrorByName() and $form_state->setError().

Issue #1533250 by YesCT, fran seva, TravisCarden, xjm, sriharsha.uppuluri | NROTC_Webmaster: Many coding standards clean-ups in locale module.

Issue #2254495 by sun, ParisLiakos, alexpott: Followup to Move language_admin_predefined_list to ConfigurableLanguageManager.

Issue #2254495 by ParisLiakos, alexpott: Move language_admin_predefined_list to ConfigurableLanguageManager.

Issue #1978918 by likin, Luxian, vijaycs85, Pancho, disasm: Convert locale_translate_import_form to a Controller.