* @param (integer|array) priority or parameter array, strings are deprecated and are ignored
*
* next args are passed as $cmd command line
- * or: Worker::add(PRIORITY_HIGH, "Notifier", "drop", $drop_id);
+ * or: Worker::add(PRIORITY_HIGH, "Notifier", Delivery::DELETION, $drop_id);
* or: Worker::add(array('priority' => PRIORITY_HIGH, 'dont_fork' => true), "CreateShadowEntry", $post_id);
*
* @return boolean "false" if proc_run couldn't be executed