Admiring the chutzpah of declaring this will be the "last breaking change". We'll see! And perhaps json schema should borrow from http header conventions of ol

Admiring the chutzpah of declaring this will be the "last breaking change". We'll see! And perhaps json schema should borrow from http header conventions of old and allow unknown elements if prefixed in some way e.g: X-my-funky-element: true