LWIP_IPV6_ADDRESS_LIFETIMES macro

LWIP_IPV6_ADDRESS_LIFETIMES==1: Keep valid and preferred lifetimes for each IPv6 address. Required for LWIP_IPV6_AUTOCONFIG. May still be enabled otherwise, in which case the application may assign address lifetimes with the appropriate macros. Addresses with no lifetime are assumed to be static. If this option is disabled, all addresses are assumed to be static.