Closest nodes to a point

[linkleonard]

Reported by llaw02 on 23 Jul 43944951 15:02 UTC
The user will provide a set of geographical coordinates and a maximum distance, and SeleXor will return a set of vessels that are within that distance from the coordinates.

This will be mostly used in part to find vessels that are along some routing path. Therefore, we should treat the world as a cylinder when performing these calculations. (i.e. east-west wrapping only, poles do not converge into a single point to avoid paths going across the poles because we aren't going to have have any nodes there...)