Elvis Costello may have come of age at a time when rock stars were supposed to kill their idols, but Nick Jonas is the kind of rock star who hugs his. Earlier this year, the 16-year-old leader of the teen-dream act the Jonas Brothers told Rolling Stone how much he admires Elvis Costello, and, like a rock & roll Make-a-Wish Foundation, we offered to get him together with his hero for a one-on-one interview. On a recent afternoon in Los Angeles, Jonas and Costello — both wearing black pants...