update heatingsystems. in progress...
Merge branch 'issue27_MixedAir' into issue107_ReviewIdeasInterfaceAndHeatingSystems
Make the electricity connection conditional.
fixed HestingSystems
make parameter m_flow and TSet final.
Merge branch 'issue27_MixedAir' into issue107_ReviewIdeasInterfaceAndHeatingSystems
Merge remote-tracking branch 'remotes/upstream/Annex60' into issue107_ReviewIdeasInterfaceAndHeatingSystems

Conflicts:
	IDEAS/Interfaces/BaseClasses/HeatingSystem.mo
	IDEAS/Interfaces/Building.mo
adapt HeatingSystems. All compiles but somes do not run.
replace thermostatic threewayvalve by a valve motor with PI Controller.
change the Thermostatic3WayValve for one using a PI controller.
Merge remote-tracking branch 'remotes/upstream/issue111_3wayValve' into issue108_HeatingSystems
filter the input of pump in Heating_Embedded_DHW_STS.mo
revert change on Thermostatic3WayValve.mo as this is handle by an other pull request
add nEmb to dummy building. Add prescribed heatflow to heatPorts.
Merge remote-tracking branch 'remotes/upstream/Interface' into issue108_HeatingSystems

Conflicts:
	IDEAS/Buildings/Examples/Structure.mo
	IDEAS/Interfaces/BaseClasses/HeatingSystem.mo
	IDEAS/Interfaces/BaseClasses/Structure.mo
	IDEAS/Interfaces/BaseClasses/VentilationSystem.mo
	IDEAS/Interfaces/Building.mo
	IDEAS/VentilationSystems/Examples.mo
	IDEAS/VentilationSystems/Ideal.mo
	IDEAS/VentilationSystems/none.mo
Merge remote-tracking branch 'remotes/upstream/issue111_3wayValve' into issue108_HeatingSystems

Conflicts:
	IDEAS/Fluid/Valves/Thermostatic3WayValve.mo
fix the Thermostatic3WayValve.mo to remove non physical factor in the k-equation.
update all heatingSystems examples. All systems are running.
Update Zone.mo

Added outer Modelica.Fluid.System system in building zone
updated ZoneExample: two zones and no m_flow boundary