Copy head@r302406 to stable/11 as part of the 11.0-RELEASE cycle.
Prune svn:mergeinfo from the new branch, as nothing has been merged
here.

Additional commits post-branch will follow.

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

MFV ntp 4.2.8p1 (r258945, r275970, r276091, r276092, r276093, r278284)

Thanks to roberto for providing pointers to wedge this into HEAD.

Approved by: roberto

Mechanically kill hard sentence breaks.

The .Nm utility

mdoc(7) police: join split punctuation to macro calls.

mdoc(7) police: use the new features of the Nm macro.

Fix cross-references which referred to xntp* instead of ntp*.

PR: 22483
Submitted by: Philipp Mergenthaler <un1i@rz.uni-karlsruhe.de>

Work around the mdoc argument limit in the Nd name description.

PR: 18465
Submitted by: Kazu TAKAMUNE <takamune@avrl.mei.co.jp>

Add selected manual pages transcribed from the HTML documentation.
Those pages which have not been transcribed are referenced as
gracefully as possible.

There is no perfect section for the ntp_* files, which document
configuration options for the NTP suite, so I'm putting them in
the same section as the pages for the utilities themselves.