Extra geometry after procedure Mesh (xbim.tessellator)

[ingral22]

Mesh generation using xbim.tessellator (Mesh method) leads to extra triangles. To reproduce the problem just open attached ifc in the Xbim Xplorer.(see screenshot and ifc in attachment).

test.zip

[r-silveira]

Hi everyone, I think I managed to fix it in this PR:
#566