message: Some minor tweaks to error reporting
  Added when trying to diagnose which I still don't understand.
diff: @@ -764,7 +764,7 @@ mod old {
  .expect("download_next called with empty queue");
  match client.stream_create(StreamType::BiDi) {
  Ok(client_stream_id) => {
  - println!("Successfully created stream id {}", client_stream_id);
  + println!("Created stream {} for {}", client_stream_id, url);
  let req = format!("GET {}\r\n", url.path());
  client
  .stream_send(client_stream_id, req.as_bytes())
  @@ -775,13 +775,13 @@ mod old {
  self.streams.insert(client_stream_id, out_file);
  true
  }
  - e @ Err(Error::StreamLimitError) | e @ Err(Error::ConnectionState) => {
  + Err(e @ Error::StreamLimitError) | Err(e @ Error::ConnectionState) => {
  println!("Cannot create stream {:?}", e);
  self.url_queue.push_front(url);
  false
  }
  Err(e) => {
  - panic!("Can't create stream {}", e);
  + panic!("Error creating stream {:?}", e);
  }
  }
  }
  