Use Mosek for better speed
Work in progress, but overall more theoretically sound

The issue was that the closest point to the ellipse is often not a
vertex of a given obstacle. In those cases, I was relying on the QP
which searched for a nearly-tangent plane through the closest vertex,
but in 3D this can actually produce planes which intersect the ellipse.
Instead, the right thing to do is to actually find the closest point on
the obstacle. Doing this is, in general, a QP, but once we've done it,
we can be assured that the tangent plane is always feasible, so we never
have to run the original plane-searching QP.
Clean out some cruft, and add some debugging data files