"lo" interface is added to /etc/network/interfaces by device search loop in casper-bottom/23networking

[Lucien Murray-Pitts]

The first "lo" interface is added by default to the /etc/network/interfaces.
However the second one is added by the for loop which searches through
  for device in /sys/class/net/*/device; do
    ...

Resulting in
  #
  auto lo
  iface lo inet loopback
  auto lo
  iface lo inet dhcp

The later uses of "ifquery" dont correctly ignore "lo" despite being passed the switch to do so.

Which later results in a crash out of ifup (from /var/log/syslog)
 dhclient[864]: Unsupported device type 772 for "lo"
 ifup[810]: Unsupported device type 772 for "lo"