ndt-javascript-client doesn't report queue status

[bchase78]

In the case that a test is in progress by another client, the server responds to the client with a SERVER_QUEUE message telling the client approximately how long it needs to wait. See https://github.com/ndt-project/ndt/wiki/NDTProtocol#queuing-clients

The current client does not report this, but instead shows no progress. The user gets the feeling that nothing is happening. It would be nice to display the status of the queue to the user, so that they are informed how long they will need to wait until testing begins