Issue #2473875 by znerol, alexpott, andypost, kim.pepper, amit.drupal, raman.b, martin107, joachim: Convert uses of $_SESSION to symfony session retrieved from the request

Issue #2829185 by vaplas, Jo Fitzgerald, anmolgoyal74, chipway, gaurav.kapoor, mark_fullmer, amit.drupal, cilefen, longwave, xjm, wturrell, anavarre: Fix spelling errors in Drupal core comments

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

Issue #2347877 by znerol, Berdir: Move DrupalKernel::initializeCookieGlobals() into a SessionConfiguration service