Add more attribution and remove unused path.

islandora.api.php

@@ -937,6 +937,8 @@ function hook_islandora_breadcrumbs_backends() {
 /**
  * Generate an array of links for breadcrumbs leading to $object, root level first.
  *
+ * Stolen shamelessly from @adam-vessey
+ *
  * @param AbstractObject $object
  *   The object to generate breadcrumbs for
  *

islandora.module

@@ -2178,7 +2178,6 @@ function islandora_create_manage_overview(AbstractObject $object) {
  * Implements hook_islandora_breadcrumbs_backends().
  */
 function islandora_islandora_breadcrumbs_backends() {
-  $module_path = drupal_get_path('module', 'islandora');
   return array(
     ISLANDORA_BREADCRUMB_LEGACY_BACKEND => array(
       'title' => t('Resource Index - Default'),