Add UN declarations of human rights.

The UN provides the [Universal Declaration of Human Rights](http://en.wikipedia.org/wiki/Universal_Declaration_of_Human_Rights) in several languages, in the public domain. Each sample is tagged with an ISO 639-1 code. I've done my best to convert them to the right ISO 639-3 codes.

https://librivox.org/group/512?primary_key=512&search_category=group&search_page=1&search_form=get_results