/**
 * Prerender function for the instance settings.
 *
 * Combine the instance, widget, and other settings into a single fieldset so
 * that elements within each group can be shown at different weights as if they
 * all had the same parent.
 */
function field_ui_field_edit_instance_pre_render($element) {
  // Merge the widget settings into the main form.
  if (isset($element['widget']['settings'])) {
    foreach (element_children($element['widget']['settings']) as $key) {
      $element['widget_' . $key] = $element['widget']['settings'][$key];
    }
    unset($element['widget']['settings']);
  }

  // Merge the instance settings into the main form.
  if (isset($element['settings'])) {
    foreach (element_children($element['settings']) as $key) {
      $element['instance_' . $key] = $element['settings'][$key];
    }
    unset($element['settings']);
  }

  return $element;
}