Cynthia Littleton Business EditorGood night, Lou.Ed Asner, the famed character actor, activist and union leader who died Sunday at the age of 91, was the last surviving member of original core cast of “The Mary Tyler Moore Show.”The ground-breaking sitcom that ran on CBS from 1970 to 1977 led Asner to become the first TV actor to play the same character in a comedy, “Mary Tyler Moore’s” irascible WJM-TV news director Lou Grant, and in the CBS drama “Lou Grant,” where Asner took center stage as