MFH (r270392, r270676, r270679, r270698): add support for subdirectories in rc.conf.d

Approved by:	re (glebius)
MFC 271048:
Always seek back to the beginning of a regular directory, even if the
previous seek location was 0.  Without this, readdir() would see
dd_loc of zero and call getdirentries() which would start reading
entries at the current seek location of the directory ignoring the
first batch of entries.  Also, rewinddir() should always seek so that
it reads the directory from the beginning to get updated entries.

PR:		192935
Approved by:	re (gjb)
Document r271095, vt(4) keymap support added to the syscons
rc(8) startup script.

Approved by:	re (implicit)
Sponsored by:	The FreeBSD Foundation
Document r271111, vt(4) enabled for PS3.

Approved by:	re (implicit)
Sponsored by:	The FreeBSD Foundation
Document r271116, ofwfb updated to work with
x11-servers/xorg-server.

Approved by:	re (implicit)
Sponsored by:	The FreeBSD Foundation
Document r271128, several performance enhancements to vt(4).

Approved by:	re (implicit)
Sponsored by:	The FreeBSD Foundation
Document r271130, sys/boot/libstand moved to 32-bit specific
directory naming convention.

Approved by:	re (implicit)
Sponsored by:	The FreeBSD Foundation
- Refine entry for r271130 since a follow-up commit
  adds 64-bit libstand.

- Document r271135, initial UEFI boot support.

- Document r271136, boot1.efi, boot1.efifat, loader.efi
  installed to /boot.

Approved by:	re (implicit)
Sponsored by:	The FreeBSD Foundation
Document r271153, KSTACK_PAGES increased 4 -> 8 on powerpc64.

Approved by:	re (implicit)
Sponsored by:	The FreeBSD Foundation
Document r271205, powerpc ATI Radeon 9700 backlight fix.

Approved by:	re (implicit)
Sponsored by:	The FreeBSD Foundation
Document r271234, mrsas(4) enabled in GENERIC for amd64
and i386.

Approved by:	re (implicit)
Sponsored by:	The FreeBSD Foundation
Document r271260, support for /etc/rc.d/<service>/
subdirectories.

Approved by:	re (implicit)
Sponsored by:	The FreeBSD Foundation
MFC r270976: Allow standalone debug for non-default ${PROG} targets

This allows WITH_DEBUG_FILES to produce standalone debug for the ELF
runtime linker.

We previously disabled standalone debug files for bsd.prog.mk consumers
that included a non-default ${PROG} target, but this is not required.

Consumers that do not support standalone debug are still handled by
disabling it for statically linked binaries, and for those that specify
a non-default binary format.

Sponsored by:	DARPA, AFRL
Approved by:	re
MFC r271047: Avoid ./ in zoneinfo entries in METALOG

Use of "find ." resulted in METALOG entries with an extra ./ -- e.g.,
./usr/share/zoneinfo/./America/Toronto.  Avoid this by using globbing
via "find *" instead.

Approved by:	re
Sponsored by:	DARPA, AFRL
Document r263720, hostname- and IP-based restrictions added
to ctld(8).

Submitted by:	trasz
Approved by:	re (implicit)
Sponsored by:	The FreeBSD Foundation
- Document 263725, ctld(8) 'portal-group' is overrideable.
- Document 263726, ctld(8) 'auth-group' default entry.

Submitted by:	trasz
Approved by:	re (implicit)
Sponsored by:	The FreeBSD Foundation