Issue333 hydraulic resistances

• see #333 (closed)
• I deleted standard parametrization for zeta and diameter!
• I also changed the parameter naming for the diamter from D to diameter according to https://github.com/RWTH-EBC/AixLib/wiki/Variable-Naming
• Please use conversion script to change paremeter in your models: convertElement("AixLib.Fluid.FixedResistances.HydraulicResistance","D","diameter")
• I also recommend the conversion script for people who are still using our old HVAC library: convertClass("HVAC.Components.HydraulicResistance.HydResistance", "AixLib.Fluid.FixedResistances.HydraulicResistance");