Changed minimum convergence criteria.  Rotation method now looks at dot product of N and F before running the minimized rotation energy scheme.  If this product is negative, the dimer has stepped over the minimum.
Changed minimum convergence criteria.  Rotation method now looks at dot product of N and F before running the minimized rotation energy scheme.  If this product is negative, the dimer has stepped over the minimum.

ajschult/etomica,ajschult/etomica,ajschult/etomica,etomica/etomica,etomica/etomica,etomica/etomica