Communicating with multiple Espruino devices

@Gordon, I think it is convenient that save() saves the port setup / mode when already setup, but it creates obviously challenges, because some things cannot be saved and need to be in onInit(){ ... } or E.on("init",function(){ ... }); anyway. I understand the concern of compatibility with the past, but for the clarity/unity of code structure and sequence, abandoning of saving pin configs should not be that big a deal (Going to chip initialized default). The code to set the pin modes is anyway there - executed immediately on upload - but masks some of the issue one can run into when dynamically changing setups... (last before save() wins... but is it the right one?)