6 add hom to buildings

[FWuellhorst]

This PR is sadly a little bit big.
I will review myself, and merge before the tutorial for a new version and release of BESMod.

New features:

• Add HOM Add HOM to Buildings #6
• Add pressure relief valve Add pressure relief valve #24 24 add pressure relief valve #28
• Increase compatibility to OpenModelica (rework KPIBus, bus-in-bus)
• Only use movers from IBPSA, not the artificial ones. Remove all artificial pumps #27
• Generally better naming
• Fix boundary issues Too many boundaries in transfer system and restrucuring of boundaries in general #25 for multiple zones. Too many boundaries in transfer system and restrucuring of boundaries in general #25 should still be kept open to avoid this error in the future.