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

mdoc: consistently spell our email addresses <foo@FreeBSD.org>

Reviewed by: ru

Update list of possible mixer devices. These devices were added to
soundcard.h more than ten years ago.

o Add "line" device to a list of mixer(8) devices.

PR: docs/112520
Submitted by: Pietro Cerutti
MFC after: 1 week

Markup fixes.

Approved by: re (blanket)

Add the -S flag which produces the -s output without
mixing field separators.

Mechanically kill hard sentence breaks.

Removed trailing whitespace.

Document changes to default output.

Assorted mdoc(7) fixes.

Approved by: re (blanket)

Implement relative mixer adjustment.

PR: 46679 (similar functionality)

The .Nm utility

Remove whitespace at EOL.

Change the behaviour of mixer slightly such that not explicitly specifying
a mixer device will set/get the master volume levels

PR: 25156
Submitted by: Tony Finch <dot@dotat.at>
Reviewed by: cg, nik

mdoc(7) police: split punctuation characters + misc fixes.

mdoc(7) police: do not split author names in the AUTHORS section.

Several cleanups:
- use getopt(3) to parse command line arguments instead of home-made incomplete
parser;
- be more verbose when error in command line encountered (i.e. incorrect
playing/recording device, incorrect recsrc syntax).

I've always wanted to be able to dump out the current values of
the mixer in a format suitable for saving and handing off to
mixer(1) at some future date to restore the settings.
Add a -s flag to do this.

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.

Remove xrefs to obosolete cdplay(1)

PR: docs/17079
Submitted by: Udo Erdelhoff <ue@nathan.ruhr.de>

Terminate .Bl with .El

Spelling fix.

PR: bin/14588
Submitted by: Christian Weisgerber <naddy@mips.rhein-neckar.de>

$Id$ -> $FreeBSD$

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

.Sh AUTHOR -> .Sh AUTHORS. Use .An/.Aq.

Use err(3).

major modifications to the mixer. currently it doesn't report errors
that it encounters (such as invalid device), but does print usage upon
this error...

but otherwise allows complex commands such as:
mixer -f /dev/mixer4 synth line 50 -rec mic +rec line =rec cd ^rec mix

Add a man page for mixer(8).