Module knot

Given a system, find any instances where a bond is 'threaded' through a ring, 
like so

                /-------       \       /                 \     /                    \----\  ---------------               \         /                       \-------/         
The algorithm works as follows:

    1. Produce a list of all cycles in the bond topology (i.e. rings)
    2. For each ring:
        a. Use boxing and distance cutoffs to reduce the number of bonds to check against
        b. Divide the ring into N triangles
        c. Check for a triangle-line intersection between the triangle and each relevant bond