Update ZFS manual pages to a mdoc(7) reimplementation.

The zfs(8) and zpool(8) manual pages now match the state of the ZFS module
and have been customized for FreeBSD.

The new texts of the "Deduplication" subsection in zfs(8), the zpool "split"
command, the zfs "dedup" property and several other missing parts have been
added from illumos or OpenSolaris snv_134 (CDDL-licensed).

The mdoc(7) reimplementation of whole manual pages, the descriptions of the
zpool "readonly" property, "zfs diff" command and descriptions of several
other missing command flags and/or options were authored by myself.

MFC after:	1 week

1 files changed, 71 insertions, 57 deletions

diff --git a/cddl/contrib/opensolaris/cmd/zdb/zdb.8 b/cddl/contrib/opensolaris/cmd/zdb/zdb.8
index 1ed1803..f84bf9a 100644
--- a/cddl/contrib/opensolaris/cmd/zdb/zdb.8
+++ b/cddl/contrib/opensolaris/cmd/zdb/zdb.8
@@ -1,65 +1,79 @@
 '\" te
+.\" Copyright (c) 2011, Martin Matuska <mm@FreeBSD.org>.
+.\" All Rights Reserved.
+.\"
+.\" The contents of this file are subject to the terms of the
+.\" Common Development and Distribution License (the "License").
+.\" You may not use this file except in compliance with the License.
+.\"
+.\" You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
+.\" or http://www.opensolaris.org/os/licensing.
+.\" See the License for the specific language governing permissions
+.\" and limitations under the License.
+.\"
+.\" When distributing Covered Code, include this CDDL HEADER in each
+.\" file and include the License file at usr/src/OPENSOLARIS.LICENSE.
+.\" If applicable, add the following below this CDDL HEADER, with the
+.\" fields enclosed by brackets "[]" replaced with your own identifying
+.\" information: Portions Copyright [yyyy] [name of copyright owner]
+.\"
 .\" Copyright (c) 2004, Sun Microsystems, Inc. All Rights Reserved.
-.\" The contents of this file are subject to the terms of the Common Development and Distribution License (the "License").  You may not use this file except in compliance with the License.
-.\" You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE or http://www.opensolaris.org/os/licensing.  See the License for the specific language governing permissions and limitations under the License.
-.\" When distributing Covered Code, include this CDDL HEADER in each file and include the License file at usr/src/OPENSOLARIS.LICENSE.  If applicable, add the following below this CDDL HEADER, with the fields enclosed by brackets "[]" replaced with your own identifying information: Portions Copyright [yyyy] [name of copyright owner]
-.\" Portions Copyright 2011 Martin Matuska <mm@FreeBSD.org>
-.TH ZDB 8 "Oct 31, 2005"
-.SH NAME
-zdb \- ZFS debugger
-.SH SYNOPSIS
-.LP
-.nf
-\fBzdb\fR \fIpool\fR
-.fi
-
-.SH DESCRIPTION
-.sp
-.LP
-The \fBzdb\fR command is used by support engineers to diagnose failures and
-gather statistics. Since the \fBZFS\fR file system is always consistent on disk
-and is self-repairing, \fBzdb\fR should only be run under the direction by a
-support engineer.
-.sp
-.LP
-If no arguments are specified, \fBzdb\fR, performs basic consistency checks on
-the pool and associated datasets, and report any problems detected.
-.sp
-.LP
+.\"
+.\" $FreeBSD$
+.\"
+.Dd November 26, 2011
+.Dt ZDB 8
+.Os
+.Sh NAME
+.Nm zdb
+.Nd ZFS debugger
+.Sh SYNOPSIS
+.Nm
+.Ar pool
+.Sh DESCRIPTION
+The
+.Nm
+command is used by support engineers to diagnose failures and
+gather statistics. Since the
+.Tn ZFS
+file system is always consistent on disk and is self-repairing,
+.Nm
+should only be run under the direction by a support engineer.
+.Pp
+If no arguments are specified,
+.Nm
+performs basic consistency checks on the pool and associated datasets, and
+report any problems detected.
+.Nm
 Any options supported by this command are internal to Sun and subject to change
 at any time.
-.SH EXIT STATUS
-.sp
-.LP
+.Sh EXIT STATUS
 The following exit values are returned:
-.sp
-.ne 2
-.na
-\fB\fB0\fR\fR
-.ad
-.RS 5n
+.Bl -tag -offset 2n -width 2n
+.It 0
 The pool is consistent.
-.RE
-
-.sp
-.ne 2
-.na
-\fB\fB1\fR\fR
-.ad
-.RS 5n
+.It 1
 An error was detected.
-.RE
-
-.sp
-.ne 2
-.na
-\fB\fB2\fR\fR
-.ad
-.RS 5n
+.It 2
 Invalid command line options were specified.
-.RE
-
-.SH SEE ALSO
-.sp
-.LP
-zfs(8), zpool(8)
+.El
+.Sh SEE ALSO
+.Xr zfs 8 ,
+.Xr zpool 8
+.Sh AUTHORS
+This manual page is a
+.Xr mdoc 7
+reimplementation of the
+.Tn OpenSolaris
+manual page
+.Em zdb(1M) ,
+modified and customized for
+.Fx
+and licensed under the
+.Tn Common Development and Distribution License
+.Pq Tn CDDL .
+.Pp
+The
+.Xr mdoc 7
+implementation of this manual page was initially written by
+.An Martin Matuska Aq mm@FreeBSD.org .