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

Previous commit accidentally left out the umask change.

Approved by: re (blanket)

The unbound-control-setup script needs to be generated so it knows where
to place the keys. Also, the correct umask is 027, not 026, although it's
not likely to make any difference.

Approved by: re (blanket)