Issue #1869548 by dawehner, jeqq, dmouse, slasher13, damiankloip, alexpott, nod_, AlxVallejo, chr.fritsch, yanniboi, effulgentsia, dixon_, -enzo-, Wim Leers, Crell, andypost, catch, Damien Tournoud, kim.pepper, linclark: Opt-in CORS support