SA-CORE-2018-005 by MichaelCu, mwop, Wim Leers, bkosborne,  cashwilliams, moshe weitzman, mlhess, xjm, larowlan, Jibran, DamienMcKenna

(cherry picked from commit 776b7f39)

Issue #2953360 by quietone, heddn, yogeshmpawar, phenaproxima, Gábor Hojtsy, maxocub, catch, alexpott, masipila: Experimental migrate_drupal_multilingual module

Issue #2962110 by samuel.mortenson, drpal, andrewmacpherson, ckrina, phenaproxima, yoroy, webchick, amateescu, chr.fritsch, starshaped, lauriii, webflo, Dennis Cohn, dawehner, seanB, rfmarcelino, DyanneNova, benjifisher, jan.stoeckler, danbohea, John Pitcairn: Add the Media Library module to Drupal core

Issue #2784921 by amateescu, timmillwood, pk188, plach, catch, Fabianx, dixon_, dawehner, borisson_, Sam152, yoroy, webchick, phenaproxima, larowlan: Add Workspaces experimental module

Issue #2713073 by harsha012, Mile23, dawehner, webflo, jibran: Add required php extensions to composer.json

Issue #2775653 by dawehner, droplet, michielnugter, Lendude, jibran, alexpott, Mixologic, klausi, juampynr, cosmicdreams, cspitzlay, justafish, drpal, larowlan, claudiu.cristea, Berdir, Mile23, andypost, xjm, mtodor: JavascriptTests with webDriver

Issue #2867960 by Eric_A, Mile23, Jo Fitzgerald, mpdonadio: Merge Component composer.json files to account for them during build

Issue #2935137 by el7cosmos, Mixologic: License "GPL-2.0+" is a deprecated SPDX license identifier, use "GPL-2.0+-only" or "GPL-2.0+-or-later" instead

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

Issue #2927806 by alexpott, mondrake, jibran, Mile23: Use PHPUnit 6 for testing when PHP version >= 7.2

Issue #2905922 by tim.plunkett, tedbow, xjm, EclipseGc, webchick, vijaycs85, larowlan, andrewmacpherson, droplet, Bojhan, mgifford, drpal, phenaproxima, DyanneNova, japerry: Implementation issue for Layout Builder

Revert "Issue #2905922 by tim.plunkett, xjm, EclipseGc, vijaycs85, webchick, larowlan, andrewmacpherson, Bojhan, droplet, mgifford, drpal, japerry, tedbow, DyanneNova, phenaproxima: Implementation issue for Layout Builder"

This reverts commit 88a22dda.

Issue #2905922 by tim.plunkett, xjm, EclipseGc, vijaycs85, webchick, larowlan, andrewmacpherson, Bojhan, droplet, mgifford, drpal, japerry, tedbow, DyanneNova, phenaproxima: Implementation issue for Layout Builder

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 #2803375 by cilefen, tedbow, saurabh-chugh, Wim Leers: Rename Outside-in module to "Settings Tray" for real

Issue #2887000 by cilefen, Mile23, mpdonadio, Eric_A: composer.json does not constrain Symfony components to minor and patch versions that are compatible with Drupal

This reverts commit 7c486399.

Issue #2831274 by slashrsm, seanB, Wim Leers, chr.fritsch, phenaproxima, naveenvalecha, marcoscano, webflo, Gábor Hojtsy, amateescu, Boobaa, iMiksu, mtodor, effulgentsia, xjm, Berdir, tim.plunkett, dawehner, tkoleary, tstoeckler, tedbow, alexpott, yoroy, catch, Bojhan, andypost, jhedstrom, jibran, aspilicious, boztek, cbr, bigbaldy, alex0412, dagmar, blueminds, ekes, Dave Reid, Sam152, bojanz, pixelmord, jonathanshaw, CTaPByK, webchick, samuel.mortenson, dbt102, dishabhadra, proweb.ua, rakesh.gectcr, rasikap, paranojik, pameeela, neardark, NormySan, Primsi, nicolas.rafaelli, romainj, royal121, vladan.me, vpeltot, woprrr, vilepickle, toni04, scheban, tduong, temkin, tim-e, mbovan, mashermike, felribeiro, giancarlosotelo, hctom, euphoric_mv, eric.duran7@gmail.com, edurenye, eelkeblok, H1ghlander, Jaesin, hkirsman, ja_ca, NickWilde, joachim, joshi.rohit100, marcingy, NerOcrO, Mixologic, jcisio, jfrederick, Lukas von Blarer, Maouna: Bring Media entity module to core as Media module

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 #2867570 by alexpott: Drupal 8.3.0 is not compatible with Drush <8.1.10 - lets declare that in composer.json

Issue #2851661 by alexpott, dawehner, xjm: Ensure that we're using the right ruleset for coding standards checking

Issue #2850797 by maxocub, dawehner, alexpott: Prepare our phpunit tests to be BC compatible with phpunit 5.x/6.x

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