added action StopAllTrains, added null checks

src/main/java/de/srsoftware/web4rail/actions/Action.java

@@ -111,6 +111,7 @@ public abstract class Action extends BaseClass {
 			FinishRoute.class,
 			TriggerContact.class,
 			TurnTrain.class,
+			StopAllTrains.class,
 			StopAuto.class,
 			SetPower.class,
 			SetRelay.class,

src/main/java/de/srsoftware/web4rail/actions/FinishRoute.java

@@ -9,7 +9,7 @@ public class FinishRoute extends Action {
 	@Override
 	public boolean fire(Context context) throws IOException {
 		Route route = context.route;
-		if (route != null) route.finish();
+		if (isSet(route)) route.finish();
 		return true;
 	}
 }

src/main/java/de/srsoftware/web4rail/actions/StopAllTrains.java

@@ -0,0 +1,14 @@
+package de.srsoftware.web4rail.actions;
+
+import java.io.IOException;
+
+import de.srsoftware.web4rail.moving.Train;
+
+public class StopAllTrains extends Action {
+
+	@Override
+	public boolean fire(Context context) throws IOException {
+		Train.list().forEach(train -> train.stopNow());
+		return true;
+	}
+}