copy edit changes from Usenix

4.4BSD snapshot (revision 8.1); add 1993 to copyright

document reno and mcast socket options & changes
to IP_HDRINCL semantics. mcast stuff based on text by Steve Deering.

macro and text revision (-mdoc version 3)

new copyright notice

add Berkeley specific copyright notice, remove subsection notation

options, updates

4.3BSD beta release manual page

manual page first distributed with 4.2BSD