Faster geometry module

[HugoFara]

The project relies on Euclidean geometry, and the code is home-made in pure Python. I think I can make it faster, with some caveats:

• We are always in 2D space, so general libraries such as NumPy are in fact slower to solve our issue (they allocate too much memory).
• Bigger Euclidean geometry library such as geometer are better than Numpy, but still slow (still N dimensional)
• Analytical libraries as SymPy are unpractical. They perform better with the paradigm "run once, get data".
• I want to give a try to shapely. It is a Python wrapper for a GEOS (C/C++), only in the Cartesian space.
• I'm open to suggestions!