Futher edits to AAG cloud sensor.  Now have basic skeleton of system in place, though not all methods are done yet.
* Primarily edited get_weather_status() method so that it writes information to a log file, though the information written is far from complete.
Edits to WeatherStation class.  Now has a is_safe() method which looks as the telemetry file and reads the SAFE/UNSAFE status from that and checks whether the information in the telemetry file is stale.