Introduced Cosm Datapoint class.
Switched to JSON in Cosm support.
Factored HTTP transaction out into a separate class.
Introduced ISO 8601 timestamp formatting.
Added posting to Cosm to the Sensor app.
Added command-line parsing to the Sensor app.
Fixed a bug in Sht21 where big values were returned as negative (because of the sign bit creep).
Started on ADC support.