As Big Daddy says so powerfully in the hit play "Cat On A Hot Tin Roof," 'there's a powerful lot of mendacity in this room." That's the sordid, shocking, stunning conclusion of a recent global polling-- the Edelman Trust Barometer, sponsored by the largest public relations firm in the world. "Less than one fifth of the general public believes business leaders and government officials will tell the truth when confronted with a difficult issue," charges Edelman in what it terms a "Crisis in Leadership."