Ability to import IFC-files (open format), not just DAE (not open format)

[Eirik]

Hi!

Please add the ability to import IFC format. This is the open format to exchange 3D models. I do not quite see the reasoning to use the DAE format as this is the closed file format from Collada.

Also, more then half of the times I try to import a DAE file, PVsyst just stops and I have to restart the program.