EspruinoWiFi module builtin?

@Gordon Thanks for the 'Storage' module! Its use should to be a great way of not having to duplicate the serialization (JSON.stringify should suffice?) and flash access in the jswrap_wifi_save/restore methods. I would still vote for a .wifiauth file (or a more generic .config perhaps?) which would get loaded and wifi connected after every reset independently of the E.setBootCode stuff.

BTW What would you think of using a leading dot (or perhaps some other character of your liking) in the filename as a nice way of distinguishing internal files.

Also thank you for the onInit() { on('connected', ...) } note, I haven't noticed that before for some reason.

@Ollie I somehow didn't spend too much time but I think I could not find a way to pass arguments/env variable values to the espruino npm's cli .js script.