Copy head (r256279) to stable/10 as part of the 10.0-RELEASE cycle.

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

Add FBSDID to all files in netinet so that people can more
easily include file version information in bug reports.

Approved by: re (kensmith)

Move universally to ANSI C function declarations, with relatively
consistent style(9)-ish layout.

/* -> /*- for license, minor formatting changes

add ECN support in layer-3.
- implement the tunnel egress rule in ip_ecn_egress() in ip_ecn.c.
make ip{,6}_ecn_egress() return integer to tell the caller that
this packet should be dropped.
- handle ECN at fragment reassembly in ip_input.c and frag6.c.

Obtained from: KAME

initialize local variable explicitly
Reviewed by: ume
Obtained from: Fujitsu guys
MFC after: 1 week

Sync with recent KAME.
This work was based on kame-20010528-freebsd43-snap.tgz and some
critical problem after the snap was out were fixed.
There are many many changes since last KAME merge.

TODO:
- The definitions of SADB_* in sys/net/pfkeyv2.h are still different
from RFC2407/IANA assignment because of binary compatibility
issue. It should be fixed under 5-CURRENT.
- ip6po_m member of struct ip6_pktopts is no longer used. But, it
is still there because of binary compatibility issue. It should
be removed under 5-CURRENT.

Reviewed by: itojun
Obtained from: KAME
MFC after: 3 weeks

sync with kame tree as of july00. tons of bug fixes/improvements.

API changes:
- additional IPv6 ioctls
- IPsec PF_KEY API was changed, it is mandatory to upgrade setkey(8).
(also syntax change)

Remove ~25 unneeded #include <sys/conf.h>
Remove ~60 unneeded #include <sys/malloc.h>

IPSEC support in the kernel.
pr_input() routines prototype is also changed to support IPSEC and IPV6
chained protocol headers.

Reviewed by: freebsd-arch, cvs-committers
Obtained from: KAME project