message: Add Monitor() calls to MINRESSolver
  I am about 80 percent confident I am passing the "right" residual vector
  to the monitor routine.
diff: @@ -1220,6 +1220,7 @@ void MINRESSolver::Mult(const Vector &b, Vector &x) const
  mfem::out << "MINRES: iteration " << setw(3) << 0 << ": ||r||_B = "
  << eta << (print_level == 3 ? " ...\n" : "\n");
  }
  + Monitor(0, eta, *z, x);
  for (it = 1; it <= max_iter; it++)
  {
  @@ -1287,6 +1288,7 @@ void MINRESSolver::Mult(const Vector &b, Vector &x) const
  mfem::out << "MINRES: iteration " << setw(3) << it << ": ||r||_B = "
  << fabs(eta) << '\n';
  }
  + Monitor(it, fabs(eta), *z, x);
  if (prec)
  {
  @@ -1311,6 +1313,7 @@ loop_end:
  {
  mfem::out << "MINRES: number of iterations: " << final_iter << '\n';
  }
  + Monitor(final_iter, final_norm, *z, x);
  #if 0
  if (print_level >= 1)
  {
  