Relative path to host base instead of absolute url

Hi Fredrik,

Your module is just awesome !

Why you don't detect relative path and suffix it thanks to the $location service ?

```
$location.protocol() + '://' + $location.host() + ':' + $location.port() + '/'
```

Related to :

```
// The URL must be absolute because of the URL blob specification  
WorkerService.setAngularUrl(url)
```
