Remove $FreeBSD$: two-line .h pattern

Remove /^\s*\*\n \*\s+\$FreeBSD\$$\n/

spdx: The BSD-2-Clause-FreeBSD identifier is obsolete, drop -FreeBSD

The SPDX folks have obsoleted the BSD-2-Clause-FreeBSD identifier. Catch
up to that fact and revert to their recommended match of BSD-2-Clause.

Discussed with: pfg
MFC After: 3 days
Sponsored by: Netflix

various: general adoption of SPDX licensing ID tags.

Mainly focus on files that use BSD 2-Clause license, however the tool I
was using misidentified many licenses so this was mostly a manual - error
prone - task.

The Software Package Data Exchange (SPDX) group provides a specification
to make it easier for automated tools to detect and summarize well known
opensource licenses. We are gradually adopting the specification, noting
that the tags are considered only advisory and do not, in any way,
superceed or replace the license texts.

No functional change intended.

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.

$Id$ -> $FreeBSD$

o Fix remaining sizeof problems for 64 bit machines.
o Allow ``set ....'' when we have multiple links but aren't in
multilink mode.
o Do a TLS when we receive a ``Open'' event in ``Closed'' state,
despite the rfc state transition table. This is clearly an
error in the RFC as TLS cannot have yet been called (without
TLF) in the ``Closed'' state.
I've posted a message to comp.protocols.ppp for confirmation.

This commit was manufactured by cvs2svn to create branch 'MP'.

Add (BSD) copyright headers.

Allow random IP number allocation to peer.
Validate the peers suggested IP by attempting to make a routing table
entry.
Give up IPCP negotiation if the peer NAKs us with an unusable IP.
Always SIOCDIFADDR then SIOCAIFADDR when configuring the tun device.
Using SIOCSIFDSTADDR allows duplicate dst addresses (which we don't
want)!!!
Allow up to 200 interface names (was 50) (now that ppp can play server
properly).
Up the version number (1.5 -> 1.6).

Cosmetic:
Log unexpected CCP packets in the CCP log rather than the ERROR log.
Log unexpected Config Reqs in the appropriate LCP/IPCP/CCP log rather
than the ERROR log.
Log failed route additions and deletions with WARN, not TCPIP.
Log the option id and length for unrecognised IPCP options.
Change some .Sq to .Ar in the man page.