Issue #2927746 by alexpott, catch, slasher13, mpdonadio, martin107, RoSk0, jibran, larowlan, pounard, Mile23, Jo Fitzgerald, deviantintegral, pritish.kumar: Update Symfony components to 3.4.*

(cherry picked from commit 47c2dda6)

Issue #2870194 by alexpott, Mile23, jibran, larowlan, tim.plunkett: Ensure that process-isolated tests can use Symfony's PHPunit bridge to catch usages of deprecated code

Issue #2909743 by jibran, mpdonadio, Mile23: Again update non-Symfony dependencies in lock file before 8.4.0

Issue #2900112 by jibran, mpdonadio, Mile23, xjm, Issue #2900112 by jibran, mpdonadio, Mile23, xjm: Update non-Symfony dependencies in lock file before 8.4.0: Update non-Symfony dependencies in lock file before 8.4.0

This reverts commit 7c486399.

Issue #2488860 by alexpott, dawehner, catch, Mile23, jgeryk, claudiu.cristea, daffie, jibran: Bring phpunit bridge into drupal and use it for unit tests and simpletest to handle Deprecation

Issue #2712647 by slasher13, klausi, catch, jibran, Manuel Garcia, alexpott, mpdonadio, naveenvalecha, neclimdul, timmillwood, webflo, dawehner, Wim Leers, pounard: Update Symfony components to ~3.2

Issue #2853201 by hampercm, dawehner: [upstream] CORS breaks form submission unless allowed origins includes site's own host

Issue #2866109 by Eric_A: Add composer installer-paths for drupal-custom-modules/themes before 8.3.0

Issue #2863411 by alexpott: Adding symfony/dom-crawler with a version limit like ">=2.8.13 <3.0" is problematic

SA-CORE-2017-001 by alexpott, benjy, Berdir, casey, cilefen, dawehner, Heine, klausi, larowlan, Mixologic, mlhess, pwolanin, samuel.mortenson, Wim Leers, xjm, YesCT

Issue #2803779 by pfrenssen, klausi, Mile23, alexpott, dawehner: Update Coder to 8.2.10 and fix errors from improved sniffs

Issue #2758737 by Mixologic, amateescu, ndf, webflo, Mile23, bojanz: Add a packages.drupal.org to root composer.json

Issue #2744463 by Mile23, dawehner, pfrenssen, joelpittet, tstoeckler, alexpott, klausi: Add phpcs, coder 8.2.8 as --dev requirements for drupal/core

This reverts commit 30de60c0.

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

This reverts commit a55b8ef1.

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

Issue #2808085 by klausi, claudiu.cristea, stof, nicolas.grekas: Pipe char in locators break Mink and Symfony element search

Issue #2763787 by pwolanin, nerdstein, rlhawk, YesCT, slasher13, tuutti, alexpott, therealssj, TravisCarden, dawehner, maximpodorov, klausi, catch, talhaparacha, Eric_A: Upgrade random_compat to latest version