Abbi Jacobson and Ilana Glazer play best friends on TV, on a sitcom called “Broad City.” They are its creators, head writers, and stars. Their characters, named Abbi and Ilana, are twenty-something stoners in New York—broke, horny, heedless, daffy, mostly benign, occasionally brilliant—who work crappy jobs, bump around town, get into mischief, and, with genial vulgarity and dirtbag charm, accidentally complicate their lives. Their manager initially pitched the show to the networks as “‘Laverne and Shirley’ meets ‘Louie,’” and it’s likely that somewhere along the line someone described it as a women’s “Workaholics,” or a chicks’ Cheech and Chong. Like anything, it owes debts to much that has come before, but it also offers something that, oddly, seems to be new, and that, to its legions of fans, is deemed…