/** Start the detector plugin manager. This includes running the plugin, if there
* is one, and if it is necessary to do so. */
void start() {
// Cannot be initialized until UserAlertManager has been created.
proxyAlert = new ProxyUserAlert(node.clientCore.alerts, false);
node.clientCore.alerts.register(portForwardAlert);
started = true;
tryMaybeRun();
}