Support FileField Sources

It would be great to support the FileField Sources module and let it work tandem with Image Widget Crop module.

FileField Sources provides a simple hook to enable it for other modules providing new widgets for uploading files.

/**
 * Implements hook_filefield_sources_widgets().
 */
function image_widget_crop_filefield_sources_widgets() {
  return array('image_widget_crop');
}