sys: Automated cleanup of cdefs and other formatting

Apply the following automated changes to try to eliminate
no-longer-needed sys/cdefs.h includes as well as now-empty
blank lines in a row.

Remove /^#if.*\n#endif.*\n#include\s+<sys/cdefs.h>.*\n/
Remove /\n+#include\s+<sys/cdefs.h>.*\n+#if.*\n#endif.*\n+/
Remove /\n+#if.*\n#endif.*\n+/
Remove /^#if.*\n#endif.*\n/
Remove /\n+#include\s+<sys/cdefs.h>\n#include\s+<sys/types.h>/
Remove /\n+#include\s+<sys/cdefs.h>\n#include\s+<sys/param.h>/
Remove /\n+#include\s+<sys/cdefs.h>\n#include\s+<sys/capsicum.h>/

Sponsored by: Netflix

sys: Remove $FreeBSD$: one-line .c pattern

Remove /^[\s*]*__FBSDID\("\$FreeBSD\$"\);?\s*\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spdx: The BSD-2-Clause-FreeBSD identifier is obsolete, drop -FreeBSD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

geli: partially revert r348709

Let's change the unsigned arguments to the signed one, but let's don't
change pointers to the array notation.

Requested by: pjd

geli: build warning fixes

Submitted by: Aaron Prieger <aprieger@llnw.com>
Reviewed by: sbruno
Differential Revision: https://reviews.freebsd.org/D11068

We don't need both _STAND and _STANDALONE. There's more places that
use _STANDALONE, so change the former to the latter.

Sponsored by: Netflix

sys/geom: 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.

improve PBKDF2 performance

The PBKDF2 in sys/geom/eli/pkcs5v2.c is around half the speed it could be

GELI's PBKDF2 uses a simple benchmark to determine a number of iterations
that will takes approximately 2 seconds. The security provided is actually
half what is expected, because an attacker could use the optimized
algorithm to brute force the key in half the expected time.

With this change, all newly generated GELI keys will be approximately 2x
as strong. Previously generated keys will talk half as long to calculate,
resulting in faster mounting of encrypted volumes. Users may choose to
rekey, to generate a new key with the larger default number of iterations
using the geli(8) setkey command.

Security of existing data is not compromised, as ~1 second per brute force
attempt is still a very high threshold.

PR: 202365
Original Research: https://jbp.io/2015/08/11/pbkdf2-performance-matters/
Submitted by: Joe Pixton <jpixton@gmail.com> (Original Version), jmg (Later Version)
Reviewed by: ed, pjd, delphij
Approved by: secteam, pjd (maintainer)
MFC after: 2 weeks
Differential Revision: https://reviews.freebsd.org/D8236

Make additional parts of sys/geom/eli more usable in userspace

The upcoming GELI support in the loader reuses parts of this code
Some ifdefs are added, and some code is moved outside of existing ifdefs

The HMAC parts of GELI are broken out into their own file, to separate
them from the kernel crypto/openssl dependant parts that are replaced
in the boot code.

Passed the GELI regression suite (tools/regression/geom/eli)
Files=20 Tests=14996
Result: PASS

Reviewed by: pjd, delphij
MFC after: 1 week
Sponsored by: ScaleEngine Inc.
Differential Revision: https://reviews.freebsd.org/D4699

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.

Remove trailing spaces.

Add GEOM_ELI class which provides GEOM providers encryption.
For features list and usage see manual page: geli(8).

Sponsored by: Wheel Sp. z o.o.
http://www.wheel.pl
MFC after: 1 week