Implements a time discrete integrator with saturation of the output between min__ and max__
[sim, y] = ld_limited_integrator4(sim, ev, u, min__, max__, Ta)
compared to ld_limited_integrator there is no delay: Ta z / (z-1)
u * - input
y * - output
min__ * - variable saturation minimum
y(k+1) = sat( y(k) + Ta*u , min__, max__ )