message: implement IExportOptions
diff: * @param options.resolution Size of facets.
  * @returns String of JavaScript containing a main() function for OpenJsCad.
  */
  - export function toOpenJsCad(modelToExport: IModel, options?: IOpenJsCadOptions): string {
  - if (!modelToExport) return '';
  + export function toOpenJsCad(itemToExport: any, options?: IOpenJsCadOptions): string {
  + if (!itemToExport) return '';
  + var modelToExport: IModel;
  var all = '';
  var depth = 0;
  var depthModel: IModel;
  extendObject(opts, options);
  + if (isModel(itemToExport)) {
  + modelToExport = itemToExport;
  + } else {
  + if (Array.isArray(itemToExport)) {
  + modelToExport = { paths: {} };
  + itemToExport.forEach((p, i) => modelToExport.paths[i] = p);
  + } else {
  + modelToExport = { paths: { 0: itemToExport } };
  + }
  + }
  +
  if (modelToExport.exporterOptions) {
  extendObject(opts, modelToExport.exporterOptions['toOpenJsCad']);
  }
  /**
  * OpenJsCad export options.
  */
  - export interface IOpenJsCadOptions extends IFindLoopsOptions {
  + export interface IOpenJsCadOptions extends IFindLoopsOptions, IExportOptions {
  /**
  * Optional depth of 3D extrusion.
  