Save the QM generated thermo to a library automatically.

Makes it easier to run simulations later without having to keep
all MOPAC output files.  Perhaps we want to compile a giant qm thermo library
and add it to the RMG-database to save computation time in the future.
Added units to wilhoit parameters for monatomic spc

Cantherm was throwing an invalid quantity error for
species like H as the units were not explicitly
mentioned for wilhoit parameters. The units added are
Cp, Cp0 and CpInf (J/(mol*K))
H (J/mol)
S (J/(mol*K))

The output was checked for H atom with primary thermo
library and looks okay.
Merge branch 'master' of github.com:GreenGroup/RMG-Py
Fixing math overflow error for Cv (vibrational)

Sometimes when the frequency is large it results in
exp(Beta*h*freq) to cause a math overflow. For now
one of the fix is to assume Cv = 0 when x > 500.

If exp(x) >> 1 then
Cv += x * x * exp(-x)
For values of x > 500 this should be very small number
and it is safe to assume it is 0.
Merge branch 'master' of github.com:GreenGroup/RMG-Py
Attempt to overcome case sensitivities for bath gas collider efficiencies.

Retain case when loading kinetics libraries.
Make logic node conversion more stringent when reading database.

Bugfix for misconversion of 'OR' group in updated cyclic ether formation family.
Allow Gaussian logs of rigid scans for cantherm
Merge branch 'master' of github.com:nyee/RMG-Py