Defensive much? There’s no denying that, even in this era of raunchy comedies, The Hangover was something different. And its massive success spawned a host of imitators: Due Date, Hall Pass, Hot Tub Time Machine and so forth. Still, that doesn’t seem enough of a reason to bring Jay-Z into it. True, his “Reminder,” the 2009 song used to soundtrack this teaser for The Hangover Part II, is a stirring rejoinder to all who may have forgotten him. But did we forget The Hangover? Or is someone a little dubious that it can sustain a sequel? Maybe that’s why they picked a track from The Blueprint 3?