1. Trimmed Surfaces were replaced with bases for *.igs and *.stp file format.
BRepLib_MakeFace method sets the TRIMMED surface of Geom_RectangularTrimmedSurface in created face.
2. Adding test case for this fix
Is2DClosed() added to reject an improper existing surface
Add OnlyClosed=Standard_False argument
Call BRepLib_FindSurface with OnlyClosed=Standard_True
fix Is2DClosed() to check intermediate points of wire in 2D
fix Is2DClosed() - correct tolerance used for the last point
fix Is2DClosed() - correct getting 2d points to compare