2) New build parameters (flags) introduced for use of IFC4x1 and IFC4x2: USE_IFC4X2 (for use of IfcBridge), USE_IFC4X1 (for use of IfcAlignment)
This explains new parameters (flags):
#ifdef USE_IFC4X2
#include "../ifcparse/Ifc4x2enum.h"
#elif USE_IFC4X1
#include "../ifcparse/Ifc4x1enum.h"
#elif USE_IFC4
#include "../ifcparse/Ifc4enum.h"
#else
#include "../ifcparse/Ifc2x3enum.h"
#endif
3) Added comment block "This file is part of IfcOpenShell. ..." at the beggining of the Ifc4x2* files.