1) Models are made compatible with Annex 60 branch.
Summary of changes:
- DummyBuilding: ventilation system needed update since ports changed
- PartialHydraulicHeating.mo: nEmbPorts equal to zero no longer allowed.
- Radiator.mo: heatflow for embedded port explicitly put to zero, since nEmb>0

2) Models for neighborhood common excercise Annex 60
- D1_annex60CE.mo added as example Buildings/D1_annex60CE.mo
- neighborhood_L.mo of annex 60 Common excercise added and simple district heating implemented