- Make sure /etc/hosts gets used before we go to the network.

   It seems that under some (all?) circumstances, the res_* functions
   are DNS ONLY - ie, they ignore /etc/nsswitch.conf and /etc/hosts.
   I can't confirm this - documentation on the resolver is sketchy (no
   surprise there).

   If res_* can't be made to use /etc/nsswitch.conf and /etc/hosts on
   ALL systems, then we have two options:

    - Load /etc/nsswitch.conf and /etc/hosts ourself, and search there
      before hitting the network.

    - Don't do SRV lookups at all if there's no nameserver specified in
      /etc/resolv.conf, and use gethostbyname() for the A lookup.

   Both these suck.