[MQTTv5] Enable use of Java's try-with-resources statement

For MQTTv3 this has already been done with #446

Signed-off-by: Alexander Straube <[email protected]>

Author: a-st

org.eclipse.paho.mqttv5.client/src/main/java/org/eclipse/paho/mqttv5/client/IMqttAsyncClient.java

@@ -24,7 +24,7 @@
 import org.eclipse.paho.mqttv5.common.MqttSubscription;
 import org.eclipse.paho.mqttv5.common.packet.MqttProperties;
 
-public interface IMqttAsyncClient {
+public interface IMqttAsyncClient extends AutoCloseable {
 
 	/**
 	 * Connects to an MQTT server using the default options.

org.eclipse.paho.mqttv5.client/src/main/java/org/eclipse/paho/mqttv5/client/IMqttClient.java

@@ -62,7 +62,7 @@
  * style. The blocking client provides compatibility with earlier versions
  * of the MQTT client.</p>
  */
-public interface IMqttClient { //extends IMqttAsyncClient {
+public interface IMqttClient extends AutoCloseable { //extends IMqttAsyncClient {
 	/**
 	 * Connects to an MQTT server using the default options.
 	 * <p>The default options are specified in {@link MqttConnectionOptions} class.

org.eclipse.paho.mqttv5.client/src/main/java/org/eclipse/paho/mqttv5/client/MqttClientPersistence.java

@@ -35,7 +35,7 @@
  * It is up to the persistence interface to log any exceptions or error information 
  * which may be required when diagnosing a persistence failure.</p>
  */
-public interface MqttClientPersistence {
+public interface MqttClientPersistence extends AutoCloseable {
 	/**
 	 * Initialise the persistent store.
 	 * If a persistent store exists for this client ID then open it, otherwise