* Use more OS-specific ways to retrieve interface information so that we
  can also parse interfaces that aren't handled by the struct ifreq stuff.
  We probably need this to handle ipv6 interface address information which
  doesn't work today.

* IPv6 name resolution is untested on Solaris due to lack of a machine to
  try this on. I'd love to hear from anyone that trys this.

* Same as above for MacOSX.

* Make validate_v4addr, validate_v6addr and validate netmask use the same
  returncodes.

