docs/129765: man 8 shutdown does not explain operation without command-line options

[Ben C. O. Grimm]

>Number:         129765
>Category:       docs
>Synopsis:       man 8 shutdown does not explain operation without command-line options
>Confidential:   no
>Severity:       non-critical
>Priority:       low
>Responsible:    freebsd-doc
>State:          open
>Quarter:        
>Keywords:       
>Date-Required:
>Class:          doc-bug
>Submitter-Id:   current-users
>Arrival-Date:   Fri Dec 19 17:00:02 UTC 2008
>Closed-Date:
>Last-Modified:
>Originator:     Ben C. O. Grimm
>Release:        7.1-PRERELEASE
>Organization:
None
>Environment:
FreeBSD hail.bengrimm.net 7.1-PRERELEASE FreeBSD 7.1-PRERELEASE #0: Mon Dec  1 17:04:32 CET 2008     root at hail.bengrimm.net:/usr/obj/usr/src/sys/HAIL  i386
>Description:
The manual for shutdown(8) describes how the command behaves using command-line options like -h or -p, but not the behavior when omitting these options, like in 'shutdown now'. 

There is a brief mention of 'bringing the system down to single-user state' (which is what 'shutdown now' actually does), but it is not explained. 

See how this might confuse users: http://forums.freebsd.org/showthread.php?p=6273
>How-To-Repeat:

>Fix:
Add a one-liner to the manual about the effect of not using command-line switches in the shutdown command.

>Release-Note:
>Audit-Trail:
>Unformatted: