Wherever he goes, Italian stud/director/mad man Omar Galanti seems to leave a circus of wild-assed sluts and crazy carnal antics in his wake. Put Omar in an untamed sexual frontier like Russia and you get something as chaotically explosive as "Omar's Ass Madness." The movie's seven hot, young, nastily uninhibited hellcats spread their mayhem in four epic scenes of anal debauchery, with Omar as ringmaster. Make that gape-master and spit-master. He finds dark, longhaired Angel Rivas in miniskirt, fishnets and heels on a Russian street and the