added return threshold getter to UAV Control

src/de/tudarmstadt/maki/simonstrator/api/uavsupport/UAVControl.java

@@ -70,4 +70,8 @@ public interface UAVControl extends CommunicationInterfaceListener {
 	public void strategyTerminated();
 
 	public Host getHost();
+
+	public double getReturnThreshold();
+
+	public double getRechargeThreshold();
 }