The he*Thermo classes have been renamed to match their corresponding
basic thermo classes. E.g., rhoThermo now corresponds to RhoThermo,
rather than heRhoThermo.
Mixture classes (e.g., pureMixtrure, coefficientMulticomponentMixture),
now have no fvMesh or volScalarField dependence. They operate on
primitive values only. All the fvMesh-dependent functionality has been
moved into the base thermodynamic classes. The 'composition()' access
function has been removed from multi-component thermo models. Functions
that were once provided by composition base classes such as
basicSpecieMixture and basicCombustionMixture are now implemented
directly in the relevant multi-component thermo base class.
