This will allow alternative methods of storing mixture information for e.g. complex transport modelling

Also remove the "<thermo" part of the names of thermodynamics packages

Thermodynamics and sub-models:  Removed "Sp" boundedness corrections on transport, replaced with "bounded Gauss" scheme

To support these changes the need for "Sp" corrections on div-terms has been
eliminated by introducing a "bounded" convection scheme which subtracts the Sp
term from the selected scheme.  The equivalent will be needed for the ddt term.

A warning message is generated for steady-state solvers in which the "bounded"
scheme is not selected for the convection terms.

so that the effect of the term on the enthalpy equation is optional

phaseModelTable superseded by PtrDictionary

New base class for fluid and solid thermo: veryBasicThermo
Base class for fluid thermo: basicThermo (derived from veryBasicThermo)
Base class for solid thermo: solidThermo (derived from veryBasicThermo)

Note in next commit basicThermo -> fluidThermo, veryBasicThermo -> basicThermo