MPL discussion

bulk moduli K or compressibilities beta=1/K for fluids and/or for solid phases. discussion
in MPL, options are Gas and NonAqueousLiquid for phases other than water. That is inconsistent, since all fluid phases could be compressible. I'd prefer to switch to WettingFluid and NonWettingFluid as the only options like in the old days, as long as we do not consider 3(+)-phase flow. In fact, we could revive Gas for future threephase flow implementations (should we ever consider that).
in MPL, should properties such as porosity, permeability, biot_coefficient, etc. be properties of the Solid phase or of the Medium? Those are used inconsistently in different processes.
use of MFront for chemical properties/laws
handle chemical thermodynamic databases for reactive transport simulations in OGS