Get Primary Country Language Code

[pfpro]

Thanks a lot for your library, its very helpful. It would be even more helpful if there was a new parameter getLanguageCode that could be used to get the primary language of a country as 2-letter (or even 5-letter) code:

// Get country language code
echo $austria->getLanguageCode();

// output 'de' OR 'de_AT'

What do you think?