Use Better Handling When Data has errors

[JonnoFTW]

Sometimes the sensor data jumps from being regular to being in an error state:

2013-01-16 10:20:00,27,34,35,41,6,9
2013-01-16 10:25:00,27,31,23,40,10,7
2013-01-16 10:30:00,19,25,17,39,8,7
2013-01-16 10:35:00,2046,2046,2046,2046,2046,2046
2013-01-16 10:40:00,2046,2046,2046,2046,2046,2046

2046 indicates errors from the sensor, we need a way of handling this rather than skipping it because the large jump in time to when the error state is cleared is anomalous.