Make logic node conversion more stringent when reading database.

Bugfix for misconversion of 'OR' group in updated cyclic ether formation family.
Merge branch 'master' of github.com:nyee/RMG-Py
Fixes for point group calculation.

These should prevent the crash at the first attempt.
Should now make a few attempts to calculate the point
group, then if that fails, it should go to the next qm
calculation option. If all else fails, it will go back to
group additivity.
Tweak to symmetry logging. See issue #130
More informative logging for InChI mismatch after running QM.
Changing what ZPE is read for compound methods

This commit changes what ZPE is read in for compound
methods like CBS-QB3 and G3.

Cantherm now reads in
E (0 K) which is E_elec + scaled ZPE
It then calculates E_elec = E (0 K) - E(ZPE)

Later it calculates the ground state energy as
E0 = E_elec + unscaled ZPE * scaling factor from input file.

This is done so to be consistent when we use different method/basis
for energy and frequency calculations (ex F12 jobs). It also
puts the onus on the user to suply the correct scaling factor for
the method.

Note: The loadZeroPointEnergy() still reads in the unscaled ZPE

closes issue #132
Merge branch 'master' of github.com:GreenGroup/RMG-Py
Allow selecting Hindered rotor fit in cantherm

Some time the best fit gives a negative energy barrier.
Therefore I added the ability to change the fit type to cosine
or fourier.

Also added an exception and error message for when this happens

Finally added more messages to the verbose log of cantherm to
help debug which rotor this occurs on.