message: Makes sure a few of the initial conf and change objects get updated
  after the first call to eval_deriv_gpu in bfgs.
diff: @@ -244,6 +244,9 @@ void bfgs_gpu(quasi_newton_aux_gpu<infoT> f, conf_gpu x, conf_gpu x_orig,
  if (idx == 0) {
  f0 = f(x, g);
  f_orig = f0;
  + g_orig = g;
  + x_orig = x;
  + p = g;
  }
  VINA_U_FOR(step, params.maxiters) {
  if (idx < g.n) {
  