Added class BoolCpt.  Its methods p and rand replace  functions condprob and condsamp.
Added class BoolCpt.  Its methods p and rand replace 
functions condprob and condsamp.

Added function event_values.

In BayesNet class, initialize instance variable evidence.

Simplified comments.


ttalviste/aima,hobson/aima,ttalviste/aima,hobson/aima,hobson/aima