added comments for needed changes
added catch for subsets of 1

* this catch used to be in kmeans, now it will catch it earlier and
just move on
moved catch for subsets of 1 site

* this catch has been moved to the KmeansAnalysis algorithm in
analysis_method.py
Merge branch 'dummy_subset' into develop

Conflicts:
	partfinder/analysis.py
	partfinder/analysis_method.py