net/dhcpcd: 6.10.2 -> 6.11.0

• pidfile directory is now created correctly at startup.
• bootp "leases" are now stored so dhcpcd can dump them.
• ARP state is kept 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 other cleanups, fully passes Coverity scan on FreeBSD!

PR: 209395
Submitted by: roy@marples.name (maintainer)