“There’s nothing special about me. There are a million guitar players and songwriters who are all really good. I’ve just been in the right place at the right time.” Photo: Jim Bennett/Getty Images Mike Campbell is a phenomenal guitar player whose prolificacy could bring many of his peers to shame. But what I took away most from Heartbreaker, his new memoir, was how much of a mediator he was. Some of the book’s most endearing stories are when Campbell, closely associated with Tom Petty, worked