post_add_single.sh: always shift the new potential at the very end (fixes issue 19)
post_add_single.sh: always shift the new potential at the very end (fixes issue 19)

MrTheodor/csg,votca/csg,junghans/csg,MrTheodor/csg,votca/csg,junghans/csg,votca/csg,junghans/csg,junghans/csg,junghans/csg,MrTheodor/csg,junghans/csg,MrTheodor/csg,votca/csg,MrTheodor/csg