util: Add functions to convert integers to addrs.
util: Add functions to convert integers to addrs.

So far we've shovelled all addresses into numeric representation and
worked on that (which obviously makes sense because it makes operations
painless) but it may make sense to convert it back to the "human
readable" notation.

Signed-off-by: aszlig <ee1aa092358634f9c53f01b5a783726c9e21b35a@redmoonstudios.org>

RedMoonStudios/hetzner