o Respect the 'dnslocalhost' option, which wasn't previously possible
  because dhcpleases clobbered /etc/hosts directly anyway.
o Align the code with how unbound does it: use a private file for
  the hosts generation.
o HUP dnsmasq at the end of the hosts file regeneration.
o `--dhcp-hostsfile' was really really wrong as /etc/hosts is read
  automatically, and the file specified here should have been adhering
  to the dhcp leases format of on `--dhcp-host' argument per line.