message: Add init function into custom widget.
diff: @@ -21,6 +21,11 @@ export class QuestionCustomWidget {
  return this.widgetJson.isFit(question);
  return false;
  }
  + public init() {
  + if (this.widgetJson.init) {
  + this.widgetJson.init();
  + }
  + }
  public activatedByChanged(activatedBy: string) {
  if (this.isLibraryLoaded() && this.widgetJson.activatedByChanged) {
  this.widgetJson.activatedByChanged(activatedBy);
  @@ -62,6 +67,7 @@ export class CustomWidgetCollection {
  }
  var customWidget = new QuestionCustomWidget(name, widgetJson);
  this.widgetsValues.push(customWidget);
  + customWidget.init();
  (<any>this).widgetsActivatedBy[name] = activatedBy;
  customWidget.activatedByChanged(activatedBy);
  this.onCustomWidgetAdded.fire(customWidget, null);
  @@ -71,7 +77,7 @@ export class CustomWidgetCollection {
  * @param widgetName the custom widget name
  * @see setActivatedBy
  */
  - public getActivatedBy(widgetName: string) {
  + public getActivatedBy(widgetName: string): string {
  var res = (<any>this).widgetsActivatedBy[widgetName];
  return res ? res : "property";
  }
  