Tweaked axes in solidsolution benchmarks
Emphasised the physical meaning of the normalisation constant in activity calculations
Adapted gibbs and chemical potential processing
Added CORK equation of state and benchmarks
Added preliminary metal-metal oxide buffer data
Updated to do list
Added Re-ReO2 buffer to test_chemical_potentials example
Add code fragments from thermopy to help with gibbs minimization
Fixed Gibbs bug created last night
Removed pressure as input variable to F(V,T) and volume as input variable to Gibbs(P,T)
Added Holland et al., 2013 lower mantle dataset
Added parsers for Holland et al., 2013 data table
Minor bug fix
Added P,T attributes and calcgibbs to solid solution class