Add permissions_delete_role, Drush perm-delete

To completed the CRUD functions for roles, and for a use case I had:

Index: modules/permissions_api/permissions_api.drush.inc
===================================================================
--- modules/permissions_api/permissions_api.drush.inc	(revision 18809)
+++ modules/permissions_api/permissions_api.drush.inc	(working copy)
@@ -25,6 +25,8 @@
         return dt("List permissions assigned to a role.");
       case 'drush:perm-create':
         return dt("Create a role.");
+      case 'drush:perm-delete':
+        return dt("Delete a role.");
     }
 }
 
@@ -98,6 +100,17 @@
     ),
   );
 
+  $items['perm-delete'] = array(
+    'callback' => 'drush_permissions_api_perm_delete',
+    'description' => dt('Delete a role.'),
+    'arguments' => array(
+      'role' => dt('The name of the role you are deleting.'),
+    ),
+    'examples' => array(
+      'drush perm-delete Admin' => dt('Delete Admin role.'),
+    ),
+  );
+
   $items['perm-list'] = array(
     'callback' => 'drush_permissions_api_perm_list',
     'description' => dt('List permissions for a role.'),
@@ -175,3 +188,11 @@
     drush_print(dt('Role !role created.', array('!role' => $role)));
   }
 }
+
+function drush_permissions_api_perm_delete() {
+  $args = func_get_args();
+  foreach($args as $role) {
+    permissions_delete_role($role);
+    drush_print(dt('Role !role delete.', array('!role' => $role)));
+  }
+}
\ No newline at end of file
Index: modules/permissions_api/permissions_api.module
===================================================================
--- modules/permissions_api/permissions_api.module	(revision 18809)
+++ modules/permissions_api/permissions_api.module	(working copy)
@@ -329,6 +329,29 @@
 }
 
 /**
+ * Helper function to create a new role in the database
+ * 
+ * @param
+ *   String representing the name of the role to be created.  Ex:  'site administrator'
+ * @return
+ *   Returns either an object representing the newly created (or previously existing) role, or FALSE if there was an error
+ */
+function permissions_delete_role($role_name) {
+  // Look up the role to see if it exists already
+  $role = permissions_get_role($role_name);
+  if($role) {
+    db_query('DELETE FROM {role} WHERE rid = %d', $role->rid);
+    db_query('DELETE FROM {permission} WHERE rid = %d', $role->rid);
+    // Update the users who have this role set:
+    db_query('DELETE FROM {users_roles} WHERE rid = %d', $role->rid);
+    watchdog('permissions_api', 'permissions_delete_role: role %rolename deleted', array('%rolename' => $role->name), WATCHDOG_ERROR);
+    return $role;
+  }
+  watchdog('permissions_api', 'permissions_delete_role: role %rolename not found', array('%rolename' => $role_name), WATCHDOG_WARNING);
+  return FALSE;
+}
+
+/**
  * This function allows a role to inherit either all the permissions of another role
  * 
  * @param