Added script to measure connetion timing

tools_scripts/benchmark/connectionTimings.groovy

@@ -0,0 +1,34 @@
+@GrabResolver(name='Paho', root='https://repo.eclipse.org/content/repositories/paho-releases/')
+@Grab(group='org.eclipse.paho', module='mqtt-client', version='0.4.0')
+
+/**
+ * Ths script is meant to measure the connection mean time from a client.
+ * It loops connecting and disconnecting to the broker.
+ * */
+
+import org.eclipse.paho.client.mqttv3.MqttClient
+import org.eclipse.paho.client.mqttv3.MqttMessage
+import org.eclipse.paho.client.mqttv3.persist.MqttDefaultFilePersistence
+
+String tmpDir = System.getProperty("java.io.tmpdir")
+MqttDefaultFilePersistence dataStore = new MqttDefaultFilePersistence(tmpDir)
+
+MqttClient client = new MqttClient("tcp://localhost:1883", "ReconnectingClient", dataStore)
+10.times {
+    println "conneting.."
+    long start = System.currentTimeMillis()
+    client.connect()
+    long time = System.currentTimeMillis() - start
+    print "took ${time} ms "
+
+    MqttMessage message = new MqttMessage('Hello world!!'.bytes)
+    message.setQos(0)
+    long startPub = System.currentTimeMillis()
+    client.getTopic("log").publish(message)
+    long pubTime = System.currentTimeMillis() - startPub
+    print " pub (qos 0): ${pubTime} ms "
+
+    client.disconnect()
+    println "disconnected"
+}
+println "Finished"