Dynamically add regions to Marionette layout

Marionette v1.0 (v1.0.2 is latest, right now) supports dynamic regions in Layouts.

var MyLayout = Marionette.Layout.extend({
  template: "#some-template"
});

var layout = new MyLayout();
layout.render();

layout.addRegion("someRegion", "#some-element");

layout.someRegion.show(new MyView());