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 #2572643 by alexpott, attiks, Jelle_S, jhodgdon: Fix Drupal.Commenting.FileComment coding standard

Issue #2502621 by Pravin Ajaaz, hussainweb, Peacog, jhodgdon, ivanjaros: Replace implement notes with inheritdoc tag

Issue #1414508 by droplet, KimNyholm, mglaman, kid_icarus, mgifford, Cottser: update system.tar.inc to latest Archive_Tar (Pear)

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

Issue #2318281 by tim.plunkett, dawehner | kim.pepper: Provide a standard way to check a plugin is an instance of the required interface.

Issue #2053153 by tim.plunkett, dawehner, damiankloip, aspilicious: Allow contrib modules to provide plugins on behalf of optional modules.

Issue #2051847 by dawehner: Fixed AnnotatedClassDiscovery::getDefinitions is critically slow when viewing nodes with comments.

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

Issue #1987298 by tim.plunkett, quicksketch: Shorten directory structure and PSR-0 namespacing for plugins.

Issue #1930020 by dawehner, Berdir, olli: Inject a class into the Core annotated discovery implementation so that namespaces can be updated.