message: Removed changes in RK4Solver::Step.
diff: @@ -94,15 +94,14 @@ void RK3SSPSolver::Step(Vector &x, double &t, double &dt)
  void RK4Solver::Init(TimeDependentOperator &_f)
  {
  ODESolver::Init(_f);
  -}
  -
  -void RK4Solver::Step(Vector &x, double &t, double &dt)
  -{
  int n = f->Width();
  y.SetSize(n);
  k.SetSize(n);
  z.SetSize(n);
  +}
  +void RK4Solver::Step(Vector &x, double &t, double &dt)
  +{
  // 0 |
  // 1/2 | 1/2
  // 1/2 | 0 1/2
  