new content:
GUI!!! - from adtrees import osead, then run osead() to see it!
ADNode.copy - creates new ADNode with the same parameters as the original one
ADTree.root_always_achievable - checks whether it is always (i.e., under any behaviour of the defender) possible for the attacker to achieve the root goal
default_domains.maxProb - domain for computing maximal probability of success over minimal attacks
default_domains.satisfiability - domain for verifying whether under given behaviour of the actors the root goal is achieved
optimizers.py - adds two functions: optimal_attacks, and optimal_countermeasures
ParetoDomain - extended to accommodate the maxProb attribute domain
BasicAssignment - when creating from a .txt file, ignore lines starting with '' (i.e., comments can be added to those files)
fixes:
BasicAssignment - int -> float