The reason of this problem is in wrong work of classifier algorithm (see the message ~0080992 to the issue #30354). Therefore, the algorithm of IntTools_FClass2d class has been improved. Namely, now orientation of the polygon is computed from area-criterion instead of angle. As result, some simplification of the method IntTools_FClass2d::Init(...) has been made.
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1. New constructor has been added to the class CSLib_Class2d. It allows applying TColgp_SequenceOfPnt2d.
2. DRAW-commands "addpolygonnode" and "polygonprops" have been created. They are covered by the test case "tests/geometry/2dpolygon/A1".
3. New method Poly::PolygonProperties(...) has been created. See help for detailed information.
4. New testgrid "lowalgos classifier" has been created.
