added aromaticity recognition for symmetry calcs

Aromaticity is now perceived in calculating cyclic symmetry numbers.
This commit copies a molecule inside `calculateCyclicSymmetryNumber`,
turns it into an rdkit object, finds all the aromatic bonds and atoms.
The same bonds and atoms in the corresponding rmg molecule object are
then redifined so that the alogorithm is using the correct information.

There is one strange thing about this fix that I dont yet understand.
The unittest thinks cyclic symmetry number of dimethylbenzene is 1
(should be 2). On my local machine, the same
`calculateCyclicSymmetryNumber` function gets it correct, at 2. Also,
i'm inadvertantly printing a bit to stdout, and not sure why it's
happening?

relevant to issues #12, #24, #119, #70, #141