Some cleaning up of the class file, and preparing for Th_inf_r
partPressure should now be able to calculate an iso_Th-curve outside the bubble-region
expansion_coeff now gives back reftemp in K, compatible with all the internal temperatures
Started to implement Th_inf_r
Reversed the switch to the water95 liqvap_density-routine. It didn't seem to work.
Implemented Th_inf_r
Added Th_inf_r to the help section