MM correction PES discontinuities

[godotalgorithm]

The most substantial PES discontinuity resulting from the C-C triple bond correction (#258) has now been fixed, but other MM corrections will also cause discontinuities in the PES because they abruptly turn on or off based on certain distance/bonding criteria and do not have a smooth distance dependence. This includes the MM corrections for HCNO (polypeptide chains), N with 3 ligands, and Si-O-H chemical units. Fixing these discontinuities has a low priority, so users should be mindful of possible PES discontinuities in systems containing these substructures.