When was the last time you were really excited by anything U2 did? You could say The Joshua Tree tour, but really that was just multimillionaires hawking nostalgia at exorbitant prices. Musically, U2 haven’t crafted anything of real weight in over a decade. The last album that most people seem to unambiguously like is All That You Can’t Leave Behind, but all that should be cited as is the ultimate example of playing it safe. Consider their previous LP, Songs of Innocence. What do you remember? Odds are the only thing that comes to mind from that fustercluck of a…