sys: Remove $FreeBSD$: two-line .h pattern

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

sys: further adoption of SPDX licensing ID tags.

Mainly focus on files that use BSD 3-Clause license.

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.

Special thanks to Wind River for providing access to "The Duke of
Highlander" tool: an older (2014) run over FreeBSD tree was useful as a
starting point.

Renumber copyright clause 4

Renumber cluase 4 to 3, per what everybody else did when BSD granted
them permission to remove clause 3. My insistance on keeping the same
numbering for legal reasons is too pedantic, so give up on that point.

Submitted by: Jan Schaumann <jschauma@stevens.edu>
Pull Request: https://github.com/freebsd/freebsd/pull/96

Drop explicit unsigned from FD_SETSIZE constant

FD_SETSIZE is often used as an argument to select or compared with an
integer file descriptor. Rather than force 3rd party software to add
explicit casts, just make it a plain (int) constant as on other
operating systems.

Previous discussion:
http://lists.freebsd.org/pipermail/freebsd-standards/2012-July/002410.html

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

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

Fix FD_ISSET() on LP64 platforms. The FD_ISSET() function/macro is
defined to return an int, but on LP64 platforms the return value of
FD_ISSET() for file descriptors with a bit-index larger than 31 would
not fit an int (due to __fd_mask being defined as an unsigned long).
The fix is to explicitly test against 0.

PR: ia64/91421
Submitted by: Tanaka Akira (akr at m17n dot org)
MFC after: 1 week

Remove advertising clause from University of California Regent's license,
per letter dated July 22, 1999.

Approved by: core

Add complete struct timeval by including <sys/_timeval.h>.

Fix the standards case by referring to __fds_bits instead of fds_bits
in FD_*() macros.

Submitted by: Marc Recht <marc@informatik.uni-bremen.de>
Approved by: re

1. Hide the internals of struct fd_set in standard namespaces.
2. Avoid referencing bcopy() and bzero(), since they may not be in
scope.

Request by: bde (1)
Submitted by: wollman (2)
Reviewed by: archie, bde
PR: 43270

Change <sys/_sigset.h> to typedef __sigset_t instead of sigset_t, so
that headers that include it can conditionalize sigset_t's visibility.

o Move select() helper macros from <sys/types.h> to <sys/select.h>.
o Include <sys/select.h> from <sys/types.h> in the __BSD_VISIBLE case,
so applications and base software can be slowly updated.
o Prototype select() in <sys/select.h>. It was previously only
prototyped in <unistd.h>.
o Add some XXX's to <sys/types.h>.

Reviewed by: -standards

Now that we have a separate header file for sigset_t, use it and avoid
the full pollution of <signal.h>.

Add some (but not all) of the things POSIX expects to be declared in
<sys/select.h>.

Do not recursively include <sys/selinfo.h> from <sys/select.h>; all in-tree
clients have been fixed. (So far as I can tell, all of the user-land
clients of <sys/select.h> do so vacuously, in the expectation that select()
might be declared there.)

Move `struct selinfo' and related functions to <sys/selinfo.h>.
Bump __FreeBSD_version to reflect the move.
For the moment, <sys/select.h> includes <sys/selinfo.h> to allow
clients time to catch up.

Changes made in preparation for SUSv2/POSIX <sys/select.h> requirements.

Back this one out until I can fix _all_ of the headers. The headers sure
are shpxed quite nicely.

None of select.h needs to be exposed to !_KERNEL.

Introduce kqueue() and kevent(), a kernel event notification facility.

Change #ifdef KERNEL to #ifdef _KERNEL in the public headers. "KERNEL"
is an application space macro and the applications are supposed to be free
to use it as they please (but cannot). This is consistant with the other
BSD's who made this change quite some time ago. More commits to come.

$Id$ -> $FreeBSD$

Back out part 1 of the MCFH that changed $Id$ to $FreeBSD$. We are not
ready for it yet.

Make the long-awaited change from $Id$ to $FreeBSD$

This will make a number of things easier in the future, as well as (finally!)
avoiding the Id-smashing problem which has plagued developers for so long.

Boy, I'm glad we're not using sup anymore. This update would have been
insane otherwise.

Added $Id$

BSD 4.4 Lite Kernel Sources