R4RS 6.10.3  (newline)              ==>  unspecific
             (newline output-port)  ==>  unspecific

Writes an end of line to OUTPUT-PORT. Exactly how this is done
differs from one operating system to another. Returns an unspecified
value. The OUTPUT-PORT argument may be omitted, in which case it
defaults to the value returned by CURRENT-OUTPUT-PORT.
