MOVIE: BAM pays homage to the late Barbara Stanwyck tonight with a screening of Forbidden. The 1932 Frank Capra-directed film (which tells the tale of a librarian who has fallen for an unobtainable/married man) was supposedly influenced by his real-life affair with the leading lady. Critic and historian Elliott Stein will discuss the film after the 6:50 screening. 4:30, 6:50 and 915pm // BAM Rose Cinemas [30 Lafayette Ave., Fort Greene] // $11 Meanwhile, the......