Removes any kickbacks from a geometry.
A kickback is defined to be four consecutive points (A, B, C, D) such that:
the distance BC is less than the distances AB and CD
the sines of the angles ABC and BCD are both less than a maximum value which may be specified by the second parameter
(Optionally) the distances from B to the line CD and from C to the line AB are both less than a maximum "width" value specified by the third parameter.
For each such kickback, the points B and C will be replaced by a new vertex midway between them.
Parameter 1 - any geometry.
Parameter 2 (Optional) - the maximum value for the sine of the angles in the kickback. If omitted, this defaults to the sine of 1 degree.
Parameter 3 (Optional) - the maximum width of the kickback.
Returns: the resulting geometry with kickbacks removed.
Note: This function does not fully support 3D geometries. Any 3D geometries will be projected down to 2 dimensions.