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

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

Add RFC 5424 syslog message output to syslogd.

- Move all of the code responsible for transmitting log messages into a
separate function, fprintlog_write().
- Instead of manually modifying a list of iovecs, add a structure
iovlist with some helper functions.
- Alter the F_FORW (UDP message forwarding) case to also use iovecs like
the other cases. Use sendmsg() instead of sendto().
- In the case of F_FORW, truncate the message to a size dependent on the
address family (AF_INET, AF_INET6), as proposed by RFC 5426.
- Move all traditional message formatting into fprintlog_bsd(). Get rid
of some of the string copying and snprintf()'ing. Simply emit more
iovecs to get the job done.
- Increase ttymsg()'s limit of 7 iovecs to 32. Add a definition for this
limit, so it can be reused by iovlist.
- Add fprintlog_rfc5424() to emit RFC 5424 formatted log entries.
- Add a "-O" command line option to enable RFC 5424 formatting. It would
have been nicer if we supported "-o rfc5424", just like on NetBSD.
Unfortunately, the "-o" flag is already used for a different purpose
on FreeBSD.
- Don't truncate hostnames in the RFC 5424 case, as suggested by that
specific RFC.

For people interested in using this, this feature can be enabled by
adding the following line to /etc/rc.conf:

syslogd_flags="-s -O rfc5424"

Differential Revision: https://reviews.freebsd.org/D15011

A new jail(8) with a configuration file, to replace the work currently done
by /etc/rc.d/jail.

Create the altix project branch. The altix project will add support
for the SGI Altix 350 to FreeBSD/ia64. The hardware used for porting
is a two-module system, consisting of a base compute module and a
CPU expansion module. SGI's NUMAFlex architecture can be an excellent
platform to test CPU affinity and NUMA-aware features in FreeBSD.

- Import the HEAD csup code which is the basis for the cvsmode work.

- Move the prototype of ttymsg() into ttymsg.h. syslogd and talkd
also use this, and they shouldn't have to have their own prototypes.

- Silence warnings about constness and signedness in ttymsg(). This
includes changing the return value to a `const char *', and changing
the types of `left' and `wret' (both byte counts) to ssize_t.

Reviewed by: bde