Rubber Bands

My latest development is the convex hull algorithm. For anyone who may be unfamiliar with a convex hull, think about it this way: imagine a set of points in the 2D plane. Now imagine stretching a rubber band so that every point is inside the rubber band. Finally, let this rubber band close in on the points. Every point that the rubber band touches is part of the convex hull, and forms a polygon such that every point is contained on or within the polygon. I used the Graham scan algorithm to perform this calculation.

This pretty much completes the functionality that I specified I would do so now it's time to go back and look over everything for usability purposes. I want to make the interface as intuitive and as simple as possible for use. After that, it's documentation stages. Finally, after all of this is done I'll look into other possibilities for the geometry module such as 3D geometry, or possibly consider working on some other stuff in the SymPy core.