Copy stable/10@r272459 to releng/10.1 as part of
the 10.1-RELEASE process.

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

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

Don't include the build date or command-line arguments in the binary.

Approved by: re (blanket)

Final #include tweak.

Approved by: re (blanket)

Numerous fixes to make Unbound compile cleanly:

- cast through void * to silence alignment warnings (presumably false
positives resulting from poor API design)

- constify a few function arguments

- move prototypes for callbacks into a common header

- now that the prototypes are in scope, fix instances of function
definitions that don't match the prototype or what the caller
actually passes

- hide a conditionally unused global variable behind the same #ifdef
that controls its use

Approved by: re (blanket)

Upgrade to 1.4.20.

Minimal subset of the unbound sources.

import unbound 1.4.17