dhcp authoritative flag

[hannesm]

dnsmasq man page has the following about dhcp-authoritative:

              Should be set when dnsmasq is definitely the only DHCP server on
              a network.  For DHCPv4, it changes the behaviour from strict RFC
              compliance so that DHCP requests on unknown leases from unknown
              hosts are not ignored. This allows new hosts to get a lease
              without a tedious timeout under all circumstances. It also
              allows dnsmasq to rebuild its lease database without each client
              needing to reacquire a lease, if the database is lost. For
              DHCPv6 it sets the priority in replies to 255 (the maximum)
              instead of 0 (the minimum).

So we may be able to change charrua, and not strictly be compliant with the RFC to avoid tedious timeout under all circumstances.

The flag itself is ignored in DNSvizor since #104.