Neither tool detected when the attribute database produces conflicting
name/IP data, silently emitting the conflicts.
confluent2hosts now warns when the same hostname is generated for
multiple different addresses within one address family (dual-stack
IPv4+IPv6 pairs stay silent), which happens naturally in -a mode when a
node has several networks without distinct per-net hostnames.
confluent2dnsmasq now warns when generated reservations share a
hostname across different IPs, reserve the same IP more than once
(dnsmasq refuses to start on a duplicate dhcp-host IP), or reuse a MAC.