Renamed tracker to world to match Matlab implementation
Removed mattest.mat from git
Added World.loadobj()
Moved World.maxrange to params
Added comparesnaps.m
Modified isolated point computation
Fixed handling of NaNs in other classes diet computation
Compute shadowing after setting up classes
Minor comment
Modified background computations
Improved plotting of background (use most frequent)
Background constructor no longer updates
Reorganized recompute() so that it would not access tracker until needed
Overhaul of splitclasses() - use simpler algorithm
Update comparesnaps() to compare shadowed[]
Major update to FrontEnd for classification -- now matches Matlab (mostly)

Also adds matlab .mat file output
Reorg