The cast of villains in “Polyphonia: Social Commentary in Contemporary Hungarian Art” warrants some serious soul searching here in the land of the freed. You have the Museum Director who refused to mount the show because of the potentially politically incriminating ideas that might arise. You have the organizers, who, though they pushed the venue onto the streets (and into various other public places), insisted on inviting artists to submit proposals for works of a sociopolitical nature with the condition that they not consider “daily politics, concrete persons, institutions, interest groups,