Experienced repertory theater actor, a former music teacher who broke into off-Broadway and Broadway work as she neared middle age and soon scored a major success with her scene-stealing wisecracks as Flo on the popular CBS sitcom, "Alice" (1976-85). Tall, lean and angular, the more typically quiet-spoken Holliday, who for years worked at disguising her native Southern accent, was able to flaunt a loud, delightfully harsh Texas twang as the sauciest of a trio of waitresses working at a small diner in Arizona. Fans were surprised to find that the actress who played the flame-haired Flo was