Improve the calling of pro function to ease model initialization

For example change from : pro = ThermoSysPro.Properties.WaterSteam.IF97.Water_Ph(P, h, mode); to : pro = ThermoSysPro.Properties.WaterSteam.IF97.Water_Ph(max(P,0), max(h,0), mode);

This allow sometimes to improve the initialization and to remove some warning messages with no physical value (ex: P<0) Obviously min can be used to set up a maximum value. Nb: the max and min function does not have any impact on performance because they do not generate event. It allows to pass of the use of a if loop which generate event. It could also be combine with homotopy operator.