In “Me and Orson Welles,” due out this fall, the teen idol dons 1930s duds, does Shakespeare and romances Claire Danes. Zac Efron doing iambic pentameter? ‘Tis so! As a teen working with Welles on a staging of “Julius Ceasar” in 1937, Efron 21, also woos an older woman (Danes) and plays the lute. Says director Richard Linklater: “He’s a natural-born performer.”