Copy head (r256279) to stable/10 as part of the 10.0-RELEASE cycle.

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

mdoc: drop redundant .Pp and .LP calls

They have no effect when coming in pairs, or before .Bl/.Bd

Note that the slave address passed to smb(4) commands must be left-justified
(LSB is 0). The iic(4) manpage probably needs similar language to describe
the format it expects.

Fixed xrefs.

Assorted markup, spelling, and grammar fixes.

Now that I learned about how all this is working together, quickly
document it for anyone else who might be interested in it.

MFC after: 2 weeks

mdoc(7) police: removed HISTORY info from the .Os call.

mdoc(7) police: remove extraneous .Pp before and/or after .Sh.

mdoc(7) police: normalize .Nd.

Remove single-space hard sentence breaks. These degrade the quality
of the typeset output, tend to make diffs harder to read and provide
bad examples for new-comers to mdoc.

Second round of config related changes to the manpages.

device blah0 -> device blah for PCI devices and busses.

$Id$ -> $FreeBSD$

Various man page cleanup:

- Sort xrefs
- FreeBSD.ORG -> FreeBSD.org
- Be consistent with section names as outlined in mdoc(7).
- Other misc mdoc cleanup.

PR: doc/13144
Submitted by: Alexey M. Zelkin <phantom@cris.net>

Add $Id$, to make it simpler for members of the translation teams to
track.

The $Id$ line is normally at the bottom of the main comment block in the
man page, separated from the rest of the manpage by an empty comment,
like so;

.\" $Id$
.\"

If the immediately preceding comment is a @(#) format ID marker than the
the $Id$ will line up underneath it with no intervening blank lines.
Otherwise, an additional blank line is inserted.

Approved by: bde

More I2C framework docs. See iicbus(4) for more info.