Copy stable/9 to releng/9.3 as part of the 9.3-RELEASE cycle.

Approved by: re (implicit)
Sponsored by: The FreeBSD Foundation

Copy head to stable/9 as part of 9.0-RELEASE release cycle.

Approved by: re (implicit)

$Id$ -> $FreeBSD$

Add (BSD) copyright headers.

Fix the CCP Type field value for DEFLATE.
(I *really* meant to do this *before* committing the
deflate changes in the first place - oops).

Pppd is horribly broken in this respect - refer to the
ppp man page for details. Ppp *WON'T* negotiate deflate
with pppd by default - you must ``enable'' and ``accept''
``pppd-deflate'' in your config.

While I'm in there, update the cftypes in ccp.c so that
we recognise some more protocols (we don't actually do
anything with them - just send a REJ).

Abstract the CCP layer a level.
Add DEFLATE support.