More additions and fixes to use CanTherm properly

The writeCanThermInp actually was writing the species
file, so that's been modified to `writeSpecFile`. The
`writeCanThermInp` needs to be implemented, and should
probably call `writeSpecFile` before it writes the
cantherm input.

This is further away than I'd like. At least now I should
be properly getting the statmech done via CanTherm for the
reactants and products. This needs to be done for the
transition state as well.