Camelcase for Tersoff_pot and BuckinghamPotLewis BuckinghamPotBush merged
BuckinghamPotLewis & BuckinghamPotBush classes are combined into BuckinghamPotential and removed.
Referecen to Lewis buckingham potential added into BuckinghamPotential
Flag check added to BuckinghamPotential
Merge branch 'master' of https://github.com/mbkumar/pymatgen