When using Vector, one can use Vector.set(int, Obj) when the 'slot' is empty. This does not work in List. I noticed when testing FiguerasSSSRFinder against the new cycle code that when FiguerasSSSRFinder was converted from using Vector to use List this was not changed and did not work at all. This patch removes the use of set().
Also will try and write some tests for FiguerasSSSRFinder at some point.