jail.conf(5): Fix and expand description of ".include".

Escape a period that caused a line not to be includesd. Also mention
that glob(3) patterns may be included, and a consequence of that.

PR: 273561
Reported by: crest@rlwinm.de
Reviewed by: emaste
MFC after: 3 days
Differential Revision: https://reviews.freebsd.org/D41723

Remove $FreeBSD$: two-line nroff pattern

Remove /^\.\\"\n\.\\"\s*\$FreeBSD\$$\n/

jail: add ".include" directive to jail.conf

Jail config files can now include literal filenames and file globs.
They can not (yet) include files based on variables/parameters.

jail.conf.5: List configuration and example files

MFC after: 3 days

jail.conf(5): emphasize where to find jail parameters

Some people expect jail.conf(5) to have a list of jail parameters.
jail(8) contains a comprehensive list of all parameters to be used during jail
invocation or in jail.conf.

Highlighting where to look for jail parameters seems a reasonable solution.

PR: 244569
Reported by: joneum@
Approved by: 0mp (manpages, mentor)
Reviewed by: debdrup
Differential Revision: https://reviews.freebsd.org/D28701

add ability to set watchdog timeout for a shutdown

This change allows to specify a watchdog(9) timeout for a system
shutdown. The timeout is activated when the watchdogd daemon is
stopped. The idea is to a prevent any indefinite hang during late
stages of the shutdown. The feature is implemented in rc.d/watchdogd,
it builds upon watchdogd -x option.

Note that the shutdown timeout is not actiavted when the watchdogd
service is individually stopped by an operator. It is also not
activated for the 'shutdown' to the single-user mode. In those cases it
is assumed that the operator knows what they are doing and they have
means to recover the system should it hang.

Significant subchanges and implementation details:
- the argument to rc.shutdown, completely unused before, is assigned to
rc_shutdown variable that can be inspected by rc scripts
- init(8) passes "single" or "reboot" as the argument, this is not
changed
- the argument is not mandatory and if it is not set then rc_shutdown is
set to "unspecified"
- however, the default jail management scripts and jail configuration
examples have been updated to pass "jail" to rc.shutdown, just in case
- the new timeout can be set via watchdogd_shutdown_timeout rc option
- for consistency, the regular timeout can now be set via
watchdogd_timeout rc option
- watchdogd_shutdown_timeout and watchdogd_timeout override timeout
specifications in watchdogd_flags
- existing configurations, where the new rc options are not set, should
keep working as before

I am not particularly wed to any of the implementation specifics.
I am open to changing or removing any of them as long as the provided
functionality is the same (or very close) to the proposed one.
For example, I think it can be implemented without using watchdogd -x,
by means of watchdog(1) alone. In that case there would be a small
window between stopping watchdogd and running watchdog, but I think that
that is acceptable.

Reviewed by: bcr (man page changes)
MFC after: 5 weeks
Relnotes: yes
Differential Revision: https://reviews.freebsd.org/D21221

Remove man page references to rndassociates.com, which has been taken over
by a domain squatter.

Bump .Dd forgotten in r261832.

MFC after: 2 weeks

Add commas (,) to the list in the SEE ALSO section, to match most other
manuals.

MFC after: 2 weeks

Add cross references between rc.conf(5) and jail.conf(5).

MFC after: 2 weeks

Minor spelling fixes.

Note that the new jail(8) will be appearing in 9.1.

General mdoc(7) and typo fixes.

PR: 167804
Submitted by: Nobuyuki Koganemaru (kogane!jp.freebsd.org)
MFC after: 3 days

mdoc: remove redundant Pp and end a display block with Ed.

Fix the dates and history as of the move to HEAD.

Update copyright dates and other whitespacey stuff.

Initial work on the new jail(8). There are more features to add, and some
cleaning up to do on existing features, but this is pretty much what the
final product will look like.