Remove $FreeBSD$: one-line .c pattern

Remove /^[\s*]*__FBSDID\("\$FreeBSD\$"\);?\s*\n/

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

Revert r228592, as the non-messy way of fixing ypxfr breaks other yp
programs (e.g. usr.sbin/rpc.yppasswdd).

Spotted by: np
MFC after: 1 week

Attempt to fix the numerous incompatible enum conversions in
libexec/ypxfr in the least disruptive way.

MFC after: 1 week

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.

Use __FBSDID vs. rcsid[].

ANSIfy and remove some dead code.

Sponsored by: DARPA, NAI Labs

Apply the following mechanical transformations in preparation for
ansification and constification:

s{\s+__P\((\(.*?\))\)}{$1}g;
s{\(\s+}{\(}g;
s{\s+\)}{\)}g;
s{\s+,}{,}g;
s{(\s+)(for|if|switch|while)\(}{$1$2 \(}g;
s{return ([^\(].*?);}{return ($1);}g;
s{([\w\)])([!=+/\*-]?=)([\w\(+-])}{$1 $2 $3}g;
s{\s+$}{\n};g

Also add $FreeBSD$ where needed.

MFC after: 1 week

$Id$ -> $FreeBSD$

Use full path in synopsis. Sort #includes. Use .Tn for NIS.

Revert $FreeBSD$ to $Id$

Make the long-awaited change from $Id$ to $FreeBSD$

This will make a number of things easier in the future, as well as (finally!)
avoiding the Id-smashing problem which has plagued developers for so long.

Boy, I'm glad we're not using sup anymore. This update would have been
insane otherwise.

Add support for rpc.ypxfrd and document it in the man page.

Also generallize the yp_dbwrite functions a little: allow the caller
to specify certain flags. I need this mostly for some changes to
rpc.yppasswdd to allow in-place updates.

Also change Makefile a little to use the same format as ypserv.

Small tweak to yp_put_record(): call the DB put routine with the
R_NOOVERWRITE flag and process return codes so that we can tell the
difference between a failure due to a duplicate database entry and
failure due to some other error.

Sync with my sources at home (these are really tiny changes):

- Fix a SEGV condition in ypxfr_main.c that reared its ugly head while I
was working on the 'parallel jobs' feature of the new yppush. After we've
completed the map transfer and created a local temporary copy, we check
the order number of the map on ypserv again to make sure it didn't change
while the transfer was in progress (map skew). If for some reason we flat
out fail to get the order number from the server, we flag this as an
error and bail, telling ypxfr_exit() to clean up our temporary files
for us. However, ypxfr_exit() tries to close the database before unkining
it, not realizing that it has already been closed prior to the skew check.
The second attempt to close the database causes a SEGV somewhere inside
the DB code.

(Well, it does on my 2.0.5 machine anyway. I haven't seen anyone modify
the DB library code in ages, so the condition is probably still there.)

To work around this, we deliberately set dbp to NULL after closing the
database and check for the condition in ypxfr_exit(), being careful to
avoid the second close if we see the NULL.

- In yp_dbwrite.c, make yp_open_db_rw() open the database with O_EXLOCK
flag set. This probably won't affect much of anything, but I feel better
having it there.

Import the new ypxfr, written by yours truly. Functionally equivalent
to the old one, except that it supports an additional option (-p path)
that lets you specify the top level path wiere your NIS maps live.
(ypserv allows you to specify a path like this, so it makes sense that
ypxfr should too. ypserv will automagically pass the -p flag to ypxfr
if you use a path other than /var/yp when you start it.)

This program uses client stub code generated by rpcgen as well as
the yp_dblookup.c module from ypserv.