config: Allow interface names for listener addresses
config: Allow interface names for listener addresses

For config options which specify listen addresses (such as --listen
and --rpclisten), all addresses associated with the interface will be
listened on.  For config options which specify dialed addresses (such
as --addpeer, --connect, --proxy, and --onion), only the first address
associated with the interface is included.

decred/dcrd,decred/dcrd