Changed behavior of piece per parcel when adding parcel to sales line masslines

In case the Mass Calculation works with Piece per Parcels the behaviour of selecting a parcel in the parcel selection has changed.

If the Mass Calculation works with Piece per Parcel (which is determined by the Mass 1 to Mass 6 options) it is tried to set Piece per Parcel in the Sales Line Massline to the selected pieces and to set Unit to 1. The Piece Per Unit (Base) keeps the value of the Base Item Unit of Measure unless, it is not compatible with the selected pieces.