ndstep_seq_minimize(): Actually call the callback
ndstep_seq_minimize(): maxiter_uni 100 -> 200, in sync with Matlab implementation
ndstep*_minimize(): Initialize xmin, fmin to point0
ndstep_minimize(): Always keep a *copy* of xmin as the original can shift with context
ndstep_minimize(): Properly deal with per-dim initialization preferring a bound to the point0