Copy stable/9 to releng/9.3 as part of the 9.3-RELEASE cycle.

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

Copy head to stable/9 as part of 9.0-RELEASE release cycle.

Approved by: re (implicit)

NOSHARED -> NO_SHARED

When nologin(8) is installed in /usr/sbin/, create a symlink from
/sbin/nologin for compatibility purposes. Also, remove the NO_NOLOGIN_LOG
option; we don't need to worry about conserving space as much on the /usr
partition.

Note that usr.sbin/nologin is not yet hooked up to the build.

Forced commit to note that files have been repocopied from
src/sbin/nologin to src/usr.sbin/nologin in preparation for
moving nologin(8) from /sbin to /usr/sbin.

Report login attempts to syslog. Due to the statically-linked nature of
nologin(8), this causes a considerable (100K) increase in the binary size,
so I've added a NO_LOGIN_LOG option which disables this.

While I'm here, s/sizeof(MESSAGE)/sizeof(MESSAGE) - 1/, in order to
avoid writing the string-terminating zero byte.

No complaints from: -current
Approved by: rwatson (mentor)

Reimplement nologin(8) as a C program. This allows us to statically
link it at low cost and avoid environment poisoning attacks associated
with LD_LIBRARY_PATH.

Suggested by: rwatson

beforeinstall -> SCRIPTS.

- Backout botched attempt to introduce MANSECT feature.
- MAN[1-9] -> MAN.

/sbin -> ${BINDIR}

Now that we have a manpage, don't have the 'clean' target be a NO-OP.

A manpage. May be the file nologin.5 should located in
src/share/man/man5.

Change `install' to `${INSTALL}' so that default install flags can be
specified in the top level Makefiles.

Convert to our man installation style. Also fixed long-standing bug
in `fastboot'/`fasthalt' in which the interpreter would hang around
after `reboot' or `halt' is run, causing an irritating ``Killed'' message.

BSD 4.4 Lite sbin Sources

Note: XNSrouted and routed NOT imported here, they shall be imported with
usr.sbin.