Remove $FreeBSD$: one-line .c comment pattern

Remove /^/[*/]\s*\$FreeBSD\$.*\n/

SPDX: mostly fixes to previous changes.

Introduce the recently approved BSD-1-Clause and replace 0BSD which
never did fit well our use cases.

Allow certain headers to be included more easily.

Spotted by: http://hacks.owlfolio.org/header-survey/

A new jail(8) with a configuration file, to replace the work currently done
by /etc/rc.d/jail.

Create the altix project branch. The altix project will add support
for the SGI Altix 350 to FreeBSD/ia64. The hardware used for porting
is a two-module system, consisting of a base compute module and a
CPU expansion module. SGI's NUMAFlex architecture can be an excellent
platform to test CPU affinity and NUMA-aware features in FreeBSD.

- Import the HEAD csup code which is the basis for the cvsmode work.

Add the userland part of the NET_RT_IFMALIST sysctl MIB. A new function,
getifmaddrs(), is added to retrieve current multicast group memberships.

Reviewed by: harti

Breath deep and take __P out of the system include files.

# This appears to not break X11, but I'm having problems compiling the
# glide part of the server with or without this patch, so I can't tell
# for sure.

add getifaddrs(3) from bsdi. this is a magic function which lets you grab
interface addresses in a portable manner, without headache of SIOCGIFCONF
or sysctl. it is in bsdi/openbsd/netbsd already.
from kame tree (actually, mandatory for latest kame tree).