Fix FTBFS on openBSD-current.
Make private functions "static"
Fix start-up order for making DHCPv6 DUID

Previously, if the DUID wasn't read from the lease-file or
script, a new one was created _after_ the helper process fork,
so for that first run, the script calls got an empty DUID.

Also, use a DUID_LL format DUID when there's no stable lease
storage, as well as when the RTC is broken. That has a chance of
evaluating to the same value on each startup.
Use random address allocation for DHCPv6 temporary addresses.
Allow interface name to specify subnets in --auth-zone.
Auth-DNS manpage update.
Fix problems when advertising deleted IPv6 prefixes.
When advertising ONLY deleted IPv6 prefixes, set router lifetime to zero.
Fix crash introduced in 376d48c7f187cd3c3e941929a4cd5e9c9903fc89
Support /4 and /6 suffixes in interface names in --auth-server
Allow empty subnet list in --auth-zone
Extend /4 and /6 syntax to --interface-name
Merge messages to .po files.
Remove arc4random, we have a good RNG and it's a portability problem.
Segfault with some CNAMEs. Also memory leak on reload of /etc/hosts.
Add missing malloc() return-code check.
Fix compiler warning.
Fix compiler warning.
Fix compiler warnings.
Fix compiler warning.