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spdx: The BSD-2-Clause-FreeBSD identifier is obsolete, drop -FreeBSD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

MFC r204075:

Style nits.

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.

Style nits.

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

Implement a work-around for poor ggate write performance.

For consistency use 'unsigned' instead of 'u_int'.

Fix ggated for platforms with 64bit size_t. The DIOCGSECTORSIZE ioctl
returns u_int.

Reported by: Javier Martín Rueda <jmrueda@diatel.upm.es>
PR: amd64/91799
MFC after: 3 days

- Handle timeouts from recv(2) properly.
- Increase timeout to 8 seconds (should be made configurable).

Reported by: Ulrich Spoerlein <uspoerlein@gmail.com>
Reported by: Christian Laursen <xi@borderworlds.dk>
PR: kern/104829
MFC after: 1 week

Reimplement ggatec/ggated applications.

Change communication protocol to be much more resistant on network
problems and to allow for much better performance.

Better performance is achieved by creating two connections between
ggatec and ggated one for sending the data and one for receiving it.
Every connection is handled by separeted thread, so there is no more
synchronous data flow (send and wait for response), now one threads
sends all requests and another receives the data.

Use two threads in ggatec(8):
- sendtd, which takes I/O requests from the kernel and sends them to the
ggated daemon on the other end;
- recvtd, which waits for ggated responses and forwards them to the kernel.

Use three threads in ggated(8):
- recvtd, which waits for I/O requests and puts them onto incoming queue;
- disktd, which takes requests from the incoming queue, does disk operations
and puts finished requests onto outgoing queue;
- sendtd, which takes finished requests from the outgoing queue and sends
responses back to ggatec.

Because there were major changes in communication protocol, there is no
backward compatibility, from now on, both client and server has to run
on 5.x or 6.x (or at least ggated should be from the same FreeBSD version
on which ggatec is running).

For Gbit networks some buffers need to be increased. I use those settings:
kern.ipc.maxsockbuf=16777216
net.inet.tcp.sendspace=8388608
net.inet.tcp.recvspace=8388608
and I use '-S 4194304 -R 4194304' options for both, ggatec and ggated.

Approved by: re (scottl)

Fix/clean up return values checking.

Print mediasize in human readable form as well.

Fix compiling on 64-bit architectures.

Stuff shared between ggate utilities.