Issue #2572613 by Malevi4, idebr, pfrenssen, Mile23, RajeevK: Fix 'Drupal.Array.Array.CommaLastItem' coding standard

Issue #2935256 by Jo Fitzgerald, voleger, kim.pepper, ibustos, Yogesh Pawar, catch, jibran: Remove all usages of drupal_get_message and drupal_set_message in modules

Issue #2857857 by vegantriathlete, Jo Fitzgerald, snehi, plach, xjm, Skabbkladden: Check use of "it's" in core to ensure proper use

Issue #2873696 by nvexler, wengerk, gido, Jo Fitzgerald, xjm: Add @internal to core classes, methods, properties to Form Classes

Issue #2688945 by tduong, amateescu, timmillwood, alexpott, joachim, xjm, yoroy, ifrik, Berdir, Gábor Hojtsy, Bojhan, webchick, cilefen, dawehner: Allow removing a module's content entities prior to module uninstallation