message: Handle stream shutdown in BeginStep with timeout
diff: @@ -637,6 +637,13 @@ static void waitForMetadataWithTimeout(SstStream Stream, float timeout_secs)
  "Returning from wait with timeout, NO TIMEOUT\n");
  return;
  }
  + if (Stream->Status != Established)
  + {
  + pthread_mutex_unlock(&Stream->DataLock);
  + CP_verbose(Stream, "Returning from wait with timeout, STREAM NO "
  + "LONGER ESTABLISHED\n");
  + return;
  + }
  gettimeofday(&now, NULL);
  CP_verbose(Stream, "timercmp, now is %ld.%06ld end is %ld.%06ld \n",
  now.tv_sec, now.tv_usec, end.tv_sec, end.tv_usec);
  @@ -990,6 +997,13 @@ extern SstStatusValue SstAdvanceStep(SstStream Stream, int mode,
  {
  MPI_Bcast(&NextTimestep, 1, MPI_LONG, 0, Stream->mpiComm);
  }
  + if (Stream->Status == PeerClosed)
  + {
  + CP_verbose(Stream,
  + "SstAdvanceStep returning EndOfStream at timestep %d\n",
  + Stream->ReaderTimestep);
  + return SstEndOfStream;
  + }
  if (NextTimestep == -1)
  {
  CP_verbose(Stream, "Advancestep timing out on no data\n");
  