Hornetq notification api: improve lightly the JMS implementation of the Notification API

In jboss-web.xml, the dependency of the war on the JMS comment topic is replaced by a dependency on the JMS Netty connection factory.

The durable subscriptions are now replaced by a non-durable subscriptions: this approach is more light and suits better our needs. We don't require the messages to be persistent; the notification API is for sending events, not messages.

As subscriptions are no more durable, a subscription recovery mechanism is now performed in the JMS implementation and this mechanism is triggered at connection lost.

Now, two JMS sessions are opened: one for the subscription and another one for the publishing. By this way, it will be more easy latter to improve the scalability by increasing the number of JMS sessions for the subscription or for the publishing.