Add .stop hook.

lib/namedQuery/namedQuery.client.js

@@ -21,10 +21,27 @@ export default class extends Base {
             throw new Meteor.Error('not-allowed', `You cannot subscribe to a resolver query`);
         }
 
+	let options = {};
+
+	if(typeof callback === 'function') {
+	    options.onReady = callback;
+	} else if(callback && callback.onReady || callback.onStop) {
+	    options = callback;
+	}
+
+	// integrate the onStop hook
+	const oldStop = options.onStop;
+	options.onStop = (...args) => {
+	    this.subscriptionHandle = null;
+
+	    if(oldStop) {
+		oldStop.apply(this, args);
+	    }
+	};
         this.subscriptionHandle = subscriptionContext.subscribe(
             this.name,
             this.params,
-            callback
+            options
         );
 
         return this.subscriptionHandle;