At least it compiles now.

Also removes stale local routes.

Julien's code should work even on 64-bit machines, but I'm superstitious.

On linux, listen to address and link change events using the netlink socket,
and react to them by dumping all local addresses or all local interfaces,
respectively, to keep babel's view up to date.
This breaks MacOS, as kernel_socket.c needs to grow a kernel_addresses()
function.