- fixed a bug which caused the MMFF parameterization code
  to segfault when a system not listed in the MMFFBndk
  table was found. THe Herschbach-Laurie fallback according
  to MMFF.V was implemented and a relevant test was added
  in testMMFFHelpers.cpp
Merge pull request #312 from ptosco/master

Herschbach-Laurie fallback implemented to fix GitHub 308