- DDNS updates state information are now stored in 'binding scopes' that

- DDNS updates state information are now stored in 'binding scopes' that
  follow the leases through their lifecycles.  This enables DDNS teardowns
  on leases that are assigned and expired inbetween a server restart (the
  state is recovered from dhcpd.leases).  Arbitrary user-specified binding
  scopes ('set var = "value";') are not yet supported.