Newton Faulkner Two performances on May 7 Borders Bookstore Performance (511 Boylston, 12:30 pm) Middle East Downstairs With Teitur and Jessie Baylin 8pm, $12 advance / $14 doors Just 23 years old and about to embark on a summer of playing huge festivals, U.K. musician Newton Faulkner might seem like the furthest thing from an “ageing superhero.” Yet that’s just one way the unassuming guitar virtuoso characterizes himself in the lyrics on his latest album,......