Address #38: Calculate single phase compositions
This adds the calculation of the single phase compositions.
A few notes:
- This fixed a bug in how the molar volume is applied to gParams. The last numElement entries in gParams are equilibrium compositions so the molar volume doesn't need to be applied there.
- The matrix to calculate the single phase compositions is really poorly conditioned with the energies ~10^10 and the compositions ~10^0. This caused problems with the matrix inversion (at least for the Leverier method). I decided to rescale the energies to remove that problem.