Lightweight package for working with 2D paths/polygons.

pypathlib is fully vectorized, so it's pretty fast. (Not quite as fast as mathplotlib.path.contains_points though.)

Relevant publications:
* S.W. Sloan, _A point-in-polygon program_. Adv. Eng. Software, Vol
7, No. 1, pp.45-47, 1985, doi:10.1016/0141-1195(85)90094-4