While many are aware that the actor and comedian Steve Martin also has a vigorous writing career, few are aware of how many of these genres he has excelled in. There are the screenplays, which include the hit films “The Jerk” and “L.A. Story”; the novels, including the bestseller “Shopgirl”; the essays for The New Yorker, and the plays, including the popular “Picasso at the Lapin Agile.” As a writer, Mr. Martin doesn’t exactly plumb the Dostoevskian depths of the human soul: He tends toward light, breezy comedy that utilizes his broad West Coast sensibility.