Baseball's Spring Training and announcements of spring and summer festival performers help combat cabin fever, so we always look forward to the New Orleans Jazz & Heritage Festival lineup release.  This year's annual New Orleans Jazz & Heritage Festival will be staged from April 24-26 and April 30-May 3d.  Big name acts announced this week include The Who, Elton John, Steve Winwood, Jimmy Buffett. Other artists of interest to Rockers include Tedeschi Trucks Band, Jimmy Vaughan, Widespread Panic, Robert Cray, Buddy Guy and Delbert McClinton.