eclipse-ditto#985 add missing javadoc, remove debug log statements

Signed-off-by: Dominik Guggemos <dominik.guggemos@bosch.io>

services/connectivity/messaging/src/main/java/org/eclipse/ditto/services/connectivity/messaging/mqtt/hivemq/AbstractMqttClientActor.java

@@ -132,7 +132,7 @@ abstract ActorRef startConsumerActor(boolean dryRun, Source source, ActorRef inb
             MqttSpecificConfig specificConfig);
 
     /**
-     * TODO
+     * @return the factory that creates new HiveMqttClients
      */
     abstract HiveMqttClientFactory<Q, ?> getClientFactory();
 
@@ -460,7 +460,6 @@ protected CompletionStage<Status.Status> startPublisherActor() {
 
     @Override
     protected void doDisconnectClient(final Connection connection, @Nullable final ActorRef origin) {
-        logger.info("doDisconnectClient");
         if (client != null) {
             final CompletionStage<ClientDisconnected> disconnectFuture = getClient().disconnect()
                     .handle((aVoid, throwable) -> {
@@ -484,7 +483,6 @@ private static ClientDisconnected getClientDisconnected(@Nullable final ActorRef
 
     @Override
     protected void cleanupResourcesForConnection() {
-        logger.info("doDisconnectClient");
         stopCommandConsumers(subscriptionHandler);
         stopChildActor(publisherActor);
         safelyDisconnectClient(client, "consumer");