Issue #2712647 by klausi, catch, slasher13, jibran, Manuel Garcia, alexpott, naveenvalecha, neclimdul, dawehner, Wim Leers, pounard: Update Symfony components to ~3.1

Issue #2572801 by alexpott, vprocessor, andriyun, andypost, chishah92, Mile23, attiks, hussainweb, klausi, dawehner, pfrenssen: Fix 'Drupal.WhiteSpace.ScopeIndent' coding standard

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 #2237101 by Mile23, cordoval, YesCT, dawehner, tim.plunkett: clean up for Core/DependencyInjection CompilerPasses

Issue #2550641 by damiankloip: Use assert() in Drupal\Core\DependencyInjection\Container::__sleep instead of trigger error

Issue #2497243 by Fabianx, znerol, fgm, Wim Leers, darol100, jhedstrom, hussainweb, pfrenssen, neclimdul, jibran, Nitesh Sethia, dawehner, chx, catch, benjy, Aki Tendo: Replace Symfony container with a Drupal one, stored in cache

Issue #2190643 by Berdir, amateescu, Xano, yched: Serializing the container is a very very bad idea, let's prevent it?.

Issue #2004282 by dawehner, smiletrl, amateescu, tim.plunkett: Injected dependencies and serialization hell .