title: RabbitMQ queue messages
body: <p>At the rabbitMQ web interface at the queue tab I see "Overview" panel where I found these:</p>
  
  <p>Queued messages :</p>
  
  <ul>
  <li>Ready </li>
  <li>Unacknowledged   </li>
  <li>Total</li>
  </ul>
  
  <p>I guess what is the "Total" messages. But what is "Ready" and  "Unacknowledged" ?
  "Ready" - messages that were delivered to the consumer?
  "Unacknowledged" - ?</p>
  
  <p>Message rates:</p>
  
  <ul>
  <li>Publish</li>
  <li>Deliver</li>
  <li>Redelivered</li>
  <li>Acknowledge  </li>
  </ul>
  
  <p>And what are these messages? Especially "Redelivered" and "Acknowledge"? What does this mean?</p>