Interface to ChemTools

[PaulWAyers]

We need to build an interface to ChemTools so that for structure along a reaction coordinate/trajectory, we can compute and visualize molecular reactivity.

This is probably primarily a ChemTools project, since if Gopt interfaces to iodata trajectories and Chemtools can analyze said trajectories, the goals would be met.

Expected Result: Interface to ChemTools. This should be achieved through iodata.