Detect when a puck.js disconnects from a browser form

Hi - those errors actually come from the puck.js library on the PC.

I think the easiest way to check for connection is to use Puck.isConnected(). I believe Puck.getConnection().on('close', function() { console.log("connection closed!") }); will work too - but to need to do that after you connected the first time

The Puck library isn't that well documented externally, but there are a bunch of comments inside it that might help: https://github.com/espruino/EspruinoWebTools/blob/master/puck.js#L446