On two May afternoons last year, as sun-seeking New Yorkers gathered at cafe tables in Bryant Park to enjoy the seasonable weather, a troupe of actors took their place behind the circulation desk in the DeWitt Wallace Periodical Room at NYPL’s Central Research Library, turned on their iPods, opened their books, and got ready to “Shuffle.”   This was Elevator Repair Service, an experimental theater company whose work “combine[s] elements of slapstick comedy, hi-tech and lo-tech design, both literary and found text, found objects and discarded furniture, and the group’s own highly developed style of choreography.” (Source: Elevator Repair Service, …