Allow support from different iso codes

[Smolky]

Hi. I think it would be interesing to allow to extract contents from different languages. In my case, I need to recover information from the Spanish wikipedia, so I changed in QueryBuilder

protected $url = "http://en.wikipedia.org/w/api.php";

to

protected $url = "http://es.wikipedia.org/w/api.php";

I think it would be interesting to set the iso code both from QueryBuilder and the Wikipedia classes. What do you think?

[Smolky]

Sorry. I don't realize this issue is duplicated.