code: function destroy(success, error){
      error = null; // should never error
      cancelScan();
      if(mediaStreamIsActive()){
        killActiveMediaStream();
      }
      backCamera = null;
      frontCamera = null;
      var preview = getVideoPreview();
      var still = getImg();
      if(preview){
        preview.remove();
      }
      if(still){
        still.remove();
      }
      success(calcStatus());
    }
docs: Reset all instance variables to their original state. This method might be useful in cases where a new camera is available, and the application needs to force the plugin to chooseCameras() again.