Fixes for advanced brep export

[JurgenQonic]

I encountered a few problems with advanced brep export and propose these fixes for them.

1. Fixed inconsistent mapping of Revit coordinates to IFC coordinates in export of RuledFace, arcs and ellipses.

2. Improved logic that organizes the inner and outer loops of a Face and fixed an orientation problem for inner loops.

I uploaded 3 sample .rvt files in the attached FaceLoopProblems.zip. One of the problems is incorrect loop orientation of inner loops. The problems occur when exporting these in IFC 4 Design Transfer View. E.g. this is one of the faces from the export of PaneledCabinet.rvt. The blue loop is the outer face loop and the red ones are the inner loops. The inner loops have the same orientation as the outer loop, which is wrong.

This is with the fixes:

From the same sample file: some Revit faces are split in multiple IFC faces, because of incorrect loop nesting detection. This is a face with one outer and one inner loop as exported by the current exporter. The result is two separate IFC faces, each with one outer loop:

With the fixes, we get a single face with an outer loop and an inner loop:

FaceLoopProblems.zip