release/tools: add bsdconfig so we have sysrc

[dch]

Summary

This solves a local problem of having sysrc available in jails, but
I would probably prefer to make sysrc available in a different package,
that doesn't require pulling in all of bsdconfig, like FreeBSD-rc maybe?

Anybody got strong opinions?

[dch]

Ivy over to you if this should go into a set or not. This is a 1.12MiB package, with sysrc as well as bsdconfig.

[ivy]

i put a fair amount of effort into not making bsdconfig a required part of the system and don't really want to see it come back. sysrc can't really be decoupled from bsdconfig, at least in the current implementation, because it's just a thin wrapper around what bsdconfig does.

i would love to see someone re-implement it to not use bsdconfig, similar to what i did for /etc/rc.subr for the service enable/disable commands.

[dch]

going with ivy's opinion on this. thanks!