/**
* Method called whenever another peer has added us to a tunnel
* the other peer initiated.
+ * Only called (once) upon reception of data with a message type which was
+ * subscribed to in GNUNET_MESH_connect. A call to GNUNET_MESH_tunnel_destroy
+ * causes te tunnel to be ignored and no further notifications are sent about
+ * the same tunnel.
*
* @param cls closure
* @param tunnel new handle to the tunnel