Attention Deadheads: the show will go on. After a five-year hiatus, the remaining members of the Grateful Dead (Bob Weir, Phil Lesh, Bill Kreutzmann and Mickey Hart) will hit the road with keyboardist Jeff Chimenti and Allman Brothers Band/Gov't Mule guitarist Warren Haynes this spring. The band, calling itself just the Dead these days, was inspired to dust off more oldies after Hart, Lesh and Weir played an Obama rally at the Warfield last Feb. The Dead will take its trip around the country sta