MFH (r276605, r282089): upgrade to latest Unbound
MFH (r276699, r276702, r277057): local control socket
MFH (r276599, r276612, r282087, r282088): build fixes

This brings in Unbound 1.5.3 from head. Local control sockets are now
supported and will be used by default for new installations. Existing
systems will continue to use TCP control sockets until the automated
setup script is re-run ("service local_unbound setup") and the service
restarted ("service local_unbound restart").

Approved by: re (kib)
Relnotes: yes

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)

Hoist all the mergeinfo up to the root in preparation for enforcing merges
to the root only. All MFC's were rerecorded to the root.

Going forward, if an MFC includes mergeinfo, it will need to be made to
the root and committed from the root. Merges with --ignore-ancestry
or diff | patch can go anywhere.

The mergeinfo in HEAD is in a bad state from years of neglect and manual
tampering and this was branched into 10.x. This confuses the coalescing
code and prevents it from doing its job.

Approved by: re (gjb, implicit)

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

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

Build and install drill(1).

Approved by: re (blanket)

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.

Revert local changes and pull in r3828 from upstream.

#if out unused functions which trip up gcc but not clang.

Upgrade to 1.6.16

Add generated files

Import LDNS and build it as an internal library.