extrude_along_path rotation problem for near vertical portions

[asdfstuart]

When a path includes a near vertical portion, the shape being extruded is rotated too much. In addition, a different extrusion results if the path is rotated before extrude_along_path is called, vs. if the extruded object is rotated after extrusion.
The attached file has five shapes generated with extrude_along_path. Individual shapes can be turned on and off using the customizer to see them individually. The desired behavior is:

• No thin necks caused by over rotation of the shape being extruded.
• The extruded shape is the same whether the path is rotated, or the object created by the path is rotated extrude_along_path_bug.py.gz extrude_along_path_bug.scad.gz .