+ * Use: Joins two endpoints together. It's OK to join endpoints
+ * which are already joined; in fact, the the right thing to do
+ * when your endpoint decides that it's not pending any more is
+ * to join it to its partner again.
+ *
+ * If the endpoints are already connected then the description
+ * string is ignored. The endpoint manager takes a copy of
+ * the string, so you don't need to keep it around.