Robert Altman 's new film The Company is the most recent addition to the list of movies concentrating on the lives of performing dancers. Jim White wonders which films - from Fred and Ginger to Strictly Ballroom - have captured and conveyed the beauty of dance most effectively. And, love them or hate them, 75 years ago Laurel and Hardy's first talkie - Unaccustomed as We Are -was released. Producer Jerome Weatheraid