message: Improve simulator logging a tiny bit
  The time stuff was not very good for tracking changes.
diff: @@ -14,7 +14,7 @@ mod drop;
  pub mod rng;
  mod taildrop;
  -use neqo_common::{qdebug, qtrace, Datagram, Encoder};
  +use neqo_common::{qdebug, qinfo, qtrace, Datagram, Encoder};
  use neqo_transport::Output;
  use rng::Random;
  use std::cell::RefCell;
  @@ -161,9 +161,7 @@ impl Simulator {
  Waiting(a) => next = Some(next.map_or(a, |b| min(a, b))),
  }
  }
  - let next = next.expect("a node cannot be idle and not done");
  - qdebug!([self.name], "advancing time by {:?}", next - now);
  - next
  + next.expect("a node cannot be idle and not done")
  }
  /// Runs the simulation.
  @@ -218,7 +216,16 @@ impl Simulator {
  }
  if dgram.is_none() {
  - now = self.next_time(now);
  + let next = self.next_time(now);
  + if next > now {
  + qinfo!(
  + [self.name],
  + "advancing time by {:?} to {:?}",
  + next - now,
  + next - start
  + );
  + now = next;
  + }
  }
  }
  }
  