Individual-level iterables

Affinity threshold list, blocklength list, and cluster methods should be all made into iterables at the individual level. If user specifies say 2 thresholds, 2 block lengths, and 2 cluster methods at 100 bootstraps, then 100 bootstrap iterations are calculated for each of the 8 versions, and aggregated into a consensus matrix. Ie 8 ISMs are created and averaged together.