MINISERIES PREMIERE: Stephen Poliakoff wrote and directed this new British miniseries import from BBC-2 –and that, alone, would make it worth watching. But there’s a lot more here, in this complex story of a fictional all-black jazz band in 1930s London, including some delightful music (original, not vintage), and strong performances. Chiwetel Ejiofor stars as bandleader Louis Lester, and supporting players include John Goodman, Anthony Head and Jacqueline Bisset, all of whom are imp