Doesn't catch the Pi dropping offline

[jjsanderson]

If WiFi plain packs in, the script continues without displaying a visible error on the dot display, beyond a POLLEN ERROR (which is common enough to have other causes assumed). Since the time continues to update, I've just spent 36 hours thinking it didn't seem as warm as the databot suggested.

Should probably check the thing's online, and display an 'OFFLINE' message if not. Some useful approaches to that here: https://stackoverflow.com/questions/3764291/how-can-i-see-if-theres-an-available-and-active-network-connection-in-python