Bugfix: was creating persons with same ids
Put initial defs into let to prevent clashes
Added newline in output of display-utterances
Simplified groups experiment
comments and docstring mods
Removed unnecess temp bind of 'propns' in receive-utterances

it was an intermediary binding in let on the way to binding new-propns.
Now I just stuck the same code into the bind line of the latter.
output filename now contains session id
fixed typo in abbrev of popco.core.constants s/b "cn"
code cleanup
comments
docstring
misc experimental changes
sims/crime3: comments
output datafile now goes into data dir
Added more variation in nets (broken)