Purge more stray embedded $FreeBSD$ strings

These do not use __FBSDID but instead use bare char arrays.

Reviewed by: imp, emaste
Differential Revision: https://reviews.freebsd.org/D41957

spdx: The BSD-2-Clause-FreeBSD identifier is obsolete, drop -FreeBSD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

Speed up pw operations that edit /etc/group or /etc/passwd

r285050 fixed a bug in pw that could lead to /etc/passwd or /etc/group
corruption on power loss. However, it fixed it by opening those files with
O_SYNC, which is very slow, especially on ZFS. This change replaces O_SYNC
with appropriately placed fsync()s instead, which is much faster. Using a
ZFS tmpdir, the time to run pw's kyua tests drops from 245s to 35s.

Reviewed by: allanjude, bapt, vangyzen, garga
Tested on pfSense by: garga
MFC after: 4 weeks
Sponsored by: Spectra Logic Corp
Differential Revision: https://reviews.freebsd.org/D8319

Close some file descriptor leaks in pw

MFC after: 4 weeks
Sponsored by: Spectra Logic Corp
Differential Revision: https://reviews.freebsd.org/D8245

Cleanup a bit includes

Rewrite parsing subcommands arguments of pw(8)

Now each subcommands checks its arguments in a dedicated functions.

This helps improving input validation, code readability/maintainability
While here:
- Add a -y option to pw userdel/usermod so it can maintain NIS servers if
nispasswd is not defined in pw.conf(5)
- Allow pw -r <rootdir> to remove directory with userdel -r
- Fix bug when renaming a user which was not renaming the user name it groups
it is a member of.
- Only parse pw.conf(5) when needed.

Remove some uneeded headers

In NIS mode first chmod(2) the temporary file and is succeed then rename(2)

Correctly set the password file mode after renaming in NIS mode

Teach pw(8) about how to use pw/gr API to reduce code duplication

MFC after: 2 months

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.

$Id$ -> $FreeBSD$

1) Do not blindly ignore file update errors which may occur due to concurrent
updating
2) Add -V <etcdir>, which allows maintaining user/group database in alternate
locations other than /etc.

Use err(3) instead of local redefinition. Add rcsid string.

Revert $FreeBSD$ to $Id$

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.

Adds optional NIS passwd file updating and optionally rebuilding
NIS maps.

Suggested by: Peter Wemm