Log Message:
Import dhcpcd-6.11.0 with the following changes:
  *  pidfile directory is now created correctly at startup.
  *  bootp "leases" are now stored so dhcpcd can dump them.
  *  ARP state is keep open so we can detect duplicates
     (currently this is only logged, no action is taken).
  *  --lastleastextend allows dhcpcd to extend a DHCP lease once
     it has expired. The lease is dropped if any other node
     claims the address.
  *  Delegated Prefix reject routes will be correctly bound to the
     loopback interface. If a delegated address uses the whole prefix,
     then the reject route is removed. If this address is removed, the
     reject route is restored.
  *  dhcp code has been reworked around a classic BOOTP structure
     instead of a fixed size DHCP structure based on a max MTU of 1500.
     Each reference to it also has a size so we know it's length.
     Adding an option to a message is now guarded via easy macros.
     Option concatenation buffer is no longer a fixed size.
  *  many more changes so that dhcpcd passes all current Coverity tests.