Made isbg return a prob vector instead of hard decisions
Do background updates on matching bg ranges even if current values is outside of active area
Modified logic for splitting large classes to avoid breaking into more than 2 parts
Improved assignment algorithm
Fixed likelihood.remove to avoid removing other -1  tracks.
Added some fuzz for comparing legsep, broke adjustLegSep() into new method
Fixed logic in calculating size of shadowed area needed
Modified world dbg()
Increased MINBGFREQ since its interpretation has changed
Added plotleftness MATLAB function