added docs for the extra-repl-information method of drscheme:language:language<%>
added docs for the extra-repl-information method of drscheme:language:language<%>

svn: r18811

mafagafogigante/racket,mafagafogigante/racket,mafagafogigante/racket,mafagafogigante/racket,mafagafogigante/racket,mafagafogigante/racket,mafagafogigante/racket,mafagafogigante/racket,mafagafogigante/racket