MFH (r266114, r266138): upgrade to latest ldns and unbound
MFH (r266139-r266143, r266145, r266149, r266150): fix props
MFH (r266179, r266180, r266193, r266238, r266777): misc cleanup
MFH (r266863): create and use /var/unbound/conf.d
MFH (r268839): import unblock-lan-zones patch from upstream
MFH (r268840): fix reverse lookups on private networks
MFH (r268883): avoid spamming source tree during build

PR: 190739 (for r268883)

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

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

Remove duplicate function declaration.

Approved by: re (blanket)

The Unbound developers have never met a pointer game they didn't like.
Fix needless deconsting.

Approved by: re (blanket)

Clean up the ntop / pton code. Part of a patch which has been submitted
upstream but not yet adopted.

Last remaining prototype issue that still hasn't been fixed upstream.

Upgrade to 1.6.16

Add generated files

Import LDNS and build it as an internal library.

import ldns 1.6.13