EspruinoWifi - Ping function / Default gateway

Hi,

It looks like something like this will work to add Ping if you need it:

wifi.ping = function(addr, callback) {
  var time;
  this.at.cmd('AT+PING="'+addr+'"\r\n',1000,function cb(d) {
    if (d && d[0]=="+") { time=d.substr(1); return cb; 
    } else if (d=="OK") callback(time); else callback();  
  });
}

but I'll see about adding that to the Espruino WiFi library.

I'm afraid I can't see a way of getting the default gateway address - but if you figure out how to get it from the ESP8266 via AT commands then I'm happy to add that.