title: camel, JMS, CLIENT_ACKNOWLEDGE mode
body: <p>I know that Camel's JMS component, for receiving messages, uses Springs DefaultMessageListenerContainer. It can be configured to use CLIENT_ACKNOWLEDGE mode for acknowledging messages. My question is, when exactly the message.acknowledge() method gets called? Is it called internally by the spring's listener container? </p>
  
  <p>Or can I somehow acknowledge message at my will?</p>
  
  <p>I'd like to avoid scenario that messages get lost because my app crashed during processing of these messages and making it transactional seems a bit too heavy for me</p>