Revision 3049

Wrote new (phase-handling) property functions in 'mixture_properties.c'; tested & compared to older (one-phase) preliminary forms of property functions from 'init_mixfuncs.c'.

Tested property functions as created by macro(s) in 'mixture_properties.c' (mathematics are the same for many properties, but I wanted to check that ), for several conditions.

Added property functions to library to find density, internal energy, enthalpy for the whole mixture and mixture phases.