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

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

Finish removing FDDI and tokenring media support.

This fixes media display for 802.11 wireless devices.

Software outside the base system that uses these media types and
defines should use #ifdef IFM_FDDI or IFM_TOKEN to include or remove
support.

Reported by: zeising
Reviewed by: emaste, kib, zeising
Tested by: zeising
Sponsored by: DARPA, AFRL
Differential Revision: https://reviews.freebsd.org/D15170

Remove support for FDDI and token ring media types in userland utilities.

Reviewed by: kib
Sponsored by: DARPA, AFRL
Differential Revision: https://reviews.freebsd.org/D15077

Remove support for FDDI networks.

Defines in net/if_media.h remain in case code copied from ifconfig is in
use elsewere (supporting non-existant media type is harmless).

Reviewed by: kib, jhb
Sponsored by: DARPA, AFRL
Differential Revision: https://reviews.freebsd.org/D15017

spdx: initial adoption of licensing ID tags.

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.

Initially, only tag files that use BSD 4-Clause "Original" license.

RelNotes: yes
Differential Revision: https://reviews.freebsd.org/D13133

Fix warnings found by -Wmising-variable-declarations.

This self-written compiler warning, which is hopefully going to be
committed into LLVM sources soon, warns about potentially missing
`static' keywords, similar to -Wmissing-prototypes.

- bin/pax: Move external declaration of chdname and s_mask into extern.h.
- bin/setfacl: Move setfacl.c-specific stuff out of setfacl.h.
- sbin/mount_fusefs: Remove char *progname; use getprogname().
- others: add `static' where possible.

Add etherswitchcfg.

Submitted by: Stefan Bethke <stb@lassitu.de>