AMOEBA No Quadrupole Optimization

This was implemented by Peter some time ago to optimize a "partial AMOEBA" force field with no quadrupoles.  Basically, if all of the quadrupole parameters are zero, the quadrupole terms are not evaluated which speeds things up.

Peter: You mentioned that we should merge this back into the master, but my most recent comparison shows that there are still differences between our branches.  Is this because we still need to merge it?