A working remote-sensor / xively gateway example for the nanode.

I couldn't get the wickeddevice.com tutorial
  http://shop.wickeddevice.com/2013/10/16/nanode-gatewayremote-sensing-tutorial-1/
to work, but this code does appear to work for me.

I don't have all the relevant libraries described here, but it should be
possible to work out again by looking at the tutorial.

Xively is not fantastically great. Often not available, even though their
status page says there's no outage.

Next step is probably to try plot.ly.
Notes.