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spdx: The BSD-2-Clause-FreeBSD identifier is obsolete, drop -FreeBSD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

MFC r201806:
Switch traceroute over to make use of proper in-kernel source
address selection.

Reviewed by: rwatson, fenner
PR: kern/139454
Tested by: Frank Steinborn (steinex nognu.de)

MFC r201897:
Correct spelling.

Submitted by: (pluknet gmail.com)

Correct spelling.

Submitted by: (pluknet gmail.com)
MFC after: 4 days
X-MFC with: r201806

Switch traceroute over to make use of proper in-kernel source
address selection.

Reviewed by: rwatson, fenner
MFC after: 1 week
X-MFCable to: stable/8, stable/7 (after r183571).
PR: kern/139454
Tested by: Frank Steinborn (steinex nognu.de)