Visualiser Closes All threads on exit now.

- Added override for exiting the Visualiser which closes all threads: such as the TCP connection.
#story[782]

visualiser/src/main/java/seng302/App.java

@@ -1,11 +1,14 @@
 package seng302;
 
 import javafx.application.Application;
+import javafx.application.Platform;
+import javafx.event.EventHandler;
 import javafx.fxml.FXMLLoader;
 import javafx.scene.Parent;
 import javafx.scene.Scene;
 import javafx.scene.layout.BorderPane;
 import javafx.stage.Stage;
+import javafx.stage.WindowEvent;
 
 public class App extends Application {
     Stage primaryStage;
@@ -22,6 +25,13 @@ public class App extends Application {
     }
 
     public void start(Stage stage) throws Exception {
+        stage.setOnCloseRequest(new EventHandler<WindowEvent>() {
+            @Override
+            public void handle(WindowEvent event) {
+                Platform.exit();
+                System.exit(0);
+            }
+        });
         FXMLLoader loader = new FXMLLoader(getClass().getResource("/scenes/main.fxml"));
         Parent root = loader.load();
         Scene scene = new Scene(root, 1200, 800);