[VFLP] New feature: Tautomerization of ligands

VFLP now can generate the tautomerization states of ligands if desired using ChemAxons JChem package. The user can specify the tautomerization options which should be used by the cxcalc tool of the JChem Suite.

One ligand can result in multiple tautomers, which will be handled automatically by VFLP.