Some minor additions

Hi,

I really like the node.js mapping but I also liked a method to directly set a value and label on a dial. I did this additions which will allow people to use something like this 

```Javascript
function dialErrorLog(err,dial) {if (!!err) return console.log('setDial: ' + err.message);};
winkapi.setDialValue(dial, 99, dialErrorLog);
winkapi.setDialLabels(dial,"Hello",dial.path,dialErrorLog);
```

Stefan