This is a residual of the $FreeBSD$ removal.

MFC After: 3 days (though I'll just run the command on the branches)
Sponsored by: Netflix

Remove /^\s*#[#!]?\s*\$FreeBSD\$.*$\n/

As result of this, a new examples package is now created.

Note, this is only effective with 'SHARED=copies' (the default),
as the 'SHARED=symlinks' mechanism will create a symlink to the
source tree version of the file(s).

Sponsored by:	The FreeBSD Foundation

and remove sysctl oids at will during runtime - they don't rely on
linker sets. Also, the node oids can be referenced by more than
one kernel user, which means that it's possible to create partially
overlapping trees.

Add sysctl contexts to help programmers manage multiple dynamic
oids in convenient way.

Please see the manpages for detailed discussion, and example module
for typical use.

This work is based on ideas and code snippets coming from many
people, among them:  Arun Sharma, Jonathan Lemon, Doug Rabson,
Brian Feldman, Kelly Yancey, Poul-Henning Kamp and others. I'd like
to specially thank Brian Feldman for detailed review and style
fixes.

PR:		kern/16928
Reviewed by:	dfr, green, phk