MFC: r321248
Update the nfsv4 man page to reflect recent changes to support
the newer RFCs (5661 and 7530). The main man changes are for the
case of "numbers in strings" for user/groups that RFC7530 allows
and avoids use of nfsuserd(8).

This is a content change.

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

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

Document the fact that an NFSv4 mount uses the host uuid to uniquely
identify the client to the server. As such, NFSv4 mounts
will break if host_enable="NO" is specified.
This is a content change.

Suggested by: lars@netapp.com
MFC after: 3 days

Document the fact that an NFSv4 mount against a volume on the same host
can result in a hung NFS server and is not recommended.
This is a content change.

MFC after: 2 weeks

Attempt to clarify that for ZFS, all file systems under
the NFSv4 root must be exported. This is because ZFS
checks exports itself.
This is a content change.

MFC after: 2 weeks

General mdoc(7) and typo fixes.

PR: 167776
Submitted by: Nobuyuki Koganemaru (kogane!jp.freebsd.org)
MFC after: 3 days

Remove superfluous paragraph macro.

Fix the nfsv4 man page to reflect the changes related to
making the new NFS client and server the default.
This is a content change.

Modify the man pages to reflect the addition of a backup
stable restart file, as done by r220510.
This is a content change.

MFC after: 2 weeks

Fix typos, spelling, formatting and mdoc mistakes found by Nobuyuki while
translating these manual pages. Minor corrections by me.

Submitted by: Nobuyuki Koganemaru <n-kogane@syd.odn.ne.jp>

mdoc: Garbage collect unused/unneeded macros

Cosmetical fixes.

Update the content of the nfsv4.4 man page to reflect the final
choice of variable names for rc.conf and option name for the
experimental server.
Also replace the inaccurate description of the nfsv4 root lines
in /etc/exports, mostly with a reference to exports(5).

Approved by: kib (mentor)

Re-format the nfsv4.4 man page so that all sentences start on a
new line.

Approved by: kib (mentor)

Modify nfsd.c to add support for the experimental nfs server.
This includes the addition of a new flag "-4" that will force
use of the experimental server with nfsv4 support in it. This
commit also adds two new man pages to the repository that are
NFSv4 specific. One describes the file used by the server to
restart nfsv4 services safely. The other is a brief overview
of nfsv4 and its setup.

Reviewed by: dfr
Approved by: kib (mentor)