package: move OpenBSM auditing into its own package

Move auditing runtime (auditd, etc.) into the new FreeBSD-audit package.
Also move the runtime OpenBSM manual pages from libbsm into auditd so
they get installed with the right package.

Add an UPDATING entry noting the new packages.

Reviewed by: imp, manu
Pull Request: https://github.com/freebsd/freebsd-src/pull/1197

Remove $FreeBSD$: one-line sh pattern

Remove /^\s*#[#!]?\s*\$FreeBSD\$.*$\n/

auditdistd: Request the OpenSSL 1.1 API

OPENSSL_API_COMPAT can be used to specify the OpenSSL API version in
use for the purpose of hiding deprecated interfaces and enabling
the appropriate deprecation notices.

This change is a NFC while we're still using OpenSSL 1.1.1 but will
avoid deprecation warnings upon the switch to OpenSSL 3.0.

A future change should migrate to use the OpenSSL 3.0 APIs.

PR: 271615
Reviewed by: emaste
Event: Kitchener-Waterloo Hackathon 202305
Sponsored by: The FreeBSD Foundation

auditdistd: Remove useless linking with libl

usr.sbin: normalize paths using SRCTOP-relative paths or :H when possible

This simplifies make logic/output

MFC after: 1 month
Sponsored by: Dell EMC Isilon

Convert usr.sbin to LIBADD
Reduce overlinking

Add -Wthread-safety to WARNS=6.

While there, add a NO_WTHREAD_SAFETY flag that can be used to disable
this specific warning flag. Disable it for auditdistd. We can easily
patch up auditdistd to have the right annotations to build, but as
auditdistd is intended to be portable across other operating systems,
it's not worth the effort.

Approved by: brueffer@

Add the Clang specific -Wmissing-variable-declarations to WARNS=6.

This compiler flag enforces that that people either mark variables
static or use an external declarations for the variable, similar to how
-Wmissing-prototypes works for functions.

Due to the fact that Yacc/Lex generate code that cannot trivially be
changed to not warn because of this (lots of yy* variables), add a
NO_WMISSING_VARIABLE_DECLARATIONS that can be used to turn off this
specific compiler warning.

Announced on: toolchain@

Merge a number of changes required to hook up OpenBSM 1.2-alpha2's
auditdistd (distributed audit daemon) to the build:

- Manual cross references
- Makefile for auditdistd
- rc.d script, rc.conf entrie
- New group and user for auditdistd; associated aliases, etc.

The audit trail distribution daemon provides reliable,
cryptographically protected (and sandboxed) delivery of audit tails
from live clients to audit server hosts in order to both allow
centralised analysis, and improve resilience in the event of client
compromises: clients are not permitted to change trail contents
after submission.

Submitted by: pjd
Sponsored by: The FreeBSD Foundation (auditdistd)