Updated method for calculating microcanonical forward and reverse rates.
Updated method for calculating microcanonical forward and reverse rates.

This update adds two features:

* Better handling of cases where only one of the two densities of states is
  known.

* Use of thermo data to get the reverse rate. This was done because the states
  data may not have all of the modes, and may be more approximate than the
  thermo data. In particular, this occurs when using RMG.

Also, rates that will be placed into the Fim matrix are updated to include
the equilibrium distribution, in line with a recent change.

pierrelb/RMG-Py,chatelak/RMG-Py,comocheng/RMG-Py,nickvandewiele/RMG-Py,KEHANG/RMG-Py,enochd/RMG-Py,nickvandewiele/RMG-Py,faribas/RMG-Py,comocheng/RMG-Py,pierrelb/RMG-Py,nyee/RMG-Py,chatelak/RMG-Py,KEHANG/RMG-Py,jwallen/MEASURE,enochd/RMG-Py,nyee/RMG-Py,faribas/RMG-Py