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spdx: The BSD-2-Clause-FreeBSD identifier is obsolete, drop -FreeBSD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

net: clean up empty lines in .c and .h files

sys: 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.

Switch to our preferred 2-clause BSD license.

Approved by: bp

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

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

Correct typos, mostly s/ a / an / where appropriate. Some whitespace cleanup,
especially in troff files.

Fix typos, mostly s/ an / a / where appropriate and a few s/an/and/
Add FreeBSD Id tag where missing.

Remove the hto(be|le)[slq] and (be|le)toh[slq] macros defined in
_KERNEL scope from "src/sys/sys/mchain.h".

Replace each occurrence of the above in _KERNEL scope with the
appropriate macro from the set of hto(be|le)(16|32|64) and
(be|le)toh(16|32|64) from "src/sys/sys/endian.h".

Tested by: tjr
Requested by: comment marked with XXX

Add more constants for future use in kernel and userland.

Obtained from: Darwin

Recongnize more error codes returned by W2K servers.

MFC after: 4 days

Add subfunction definition for future use.

MFC after: 2 weeks

Spelling fixes.

PR: kern/33131
Submitted by: Anders Andersson <anders@hack.org>
MFC after: 1 week

Use proper endian conversions.

Obtained from: Mac OS X
MFC after: 1 week

Import kernel part of SMB/CIFS requester.
Add smbfs(CIFS) filesystem.

Userland part will be in the ports tree for a while.

Obtained from: smbfs-1.3.7-dev package.