Add support for language translation.

Addresses #28 by adding a new `l` URL parameter for the source language. For example:

[http://localhost:8080/api/georef?q=ciudad de México&l=es](http://localhost:8080/api/georef?q=ciudad%20de%20M%C3%A9xico&l=es)

Gives you this:

```json
{
   "location":{
      "name":"Mexico City"
   },
   "georefs":[
      {
         "uncertainty":37571.0,
         "feature":{
            "geometry":{
               "type":"Point",
               "coordinates":[
                  -99.1518319,
                  19.3202213
               ]
            },
            "type":"Feature",
            "bbox":[
               -99.3641835,
               19.0482787,
               -98.9401855,
               19.5919189
            ]
         }
      },
      {
         "uncertainty":7390.0,
         "feature":{
            "geometry":{
               "type":"Point",
               "coordinates":[
                  -91.8644551,
                  39.1597293
               ]
            },
            "type":"Feature",
            "bbox":[
               -91.923513,
               39.1116249,
               -91.8054779,
               39.20780389999999
            ]
         }
      }
   ]
}
```