Use activePeople for npeople
Removed obsolete getNextX()
Clean up getLegSepLike()
Added PROTOCOL.txt to git
Made UNITSPERM float

Primarily so dividing by it doesn’t accidental end up with integer
truncation
Don't let position variance go below sensor variance

Otherwise, estimates are too sharp, constrain positions excessively
Use simpler legsep likelihood function when positions have high variance
Refactor Person using separate Legs class
Update /pf/set messages
Removed obsolete classes field from matlab output
Added empty constructor for LookupTable()
Reorganized parameters, added some new ones
Updated PROTOCOL
Modified person.m to handle separate likelihood window/leg
Turn on tracker debugging
Use tracker.bglike instead of copying from vis