Magnetosheath Boundary Correction

As it is not unusual that modelled magnetopause/bow shock (currently Shue et al. (1998) magnetopause model and Jelinek et al. (2012) bow shock model, respectively) does not match with observed magnetosheath boundaries, we added manual boundary adjust function.

As described in Usage, mpoff and bsoff parameters adjust MP/BS location in radial direction (positive is Sun-side, negative is Earth-side) in Earth radii at each input point.