message: added jscad.io & opentype.js
diff: // Definitions: https://github.com/DefinitelyTyped/DefinitelyTyped
  /// <reference path="external/jscad/csg.d.ts" />
  +/// <reference path="external/jscad/io.d.ts" />
  /// <reference path="external/jscad/stl-serializer.d.ts" />
  +/// <reference types="opentype.js" />
  