Add deprecation message to the superfluous DS-COMPOSITE-MODEL parser.

includes/utilities.inc

@@ -636,6 +636,9 @@ function islandora_system_settings_form_default_value($name, $default_value, arr
  *       is optional.
  */
 function islandora_get_comp_ds_mappings($pid) {
+  $message = islandora_deprecated('7.x-1.2', t('Refactor to use the more flexible islandora_get_datastreams_requirements_from_content_model().'));
+  trigger_error(filter_xss($message), E_USER_DEPRECATED);
+
   $cm_object = islandora_object_load($pid);
   if (!isset($cm_object) || !isset($cm_object['DS-COMPOSITE-MODEL'])) {
     return FALSE;