The Library of Congress will no longer use the words “illegal” and “alien” to describe undocumented immigrants after Dartmouth College students petitioned for the change, the group said Wednesday.Instead, the Library of Congress will use the terms “non-citizen” and “unauthorized immigrants” in subject headings to refer to undocumented immigrants.Students, faculty and librarians with the Dartmouth Coalition for Immigration Reform, Equality and DREAMers, or CoFIRED, petitioned for the change for…