Description:

With Numbers_Words class you can convert numbers written in arabic
digits to words in several languages. You can convert an integer
between -infinity and infinity. If your system does not support such
long numbers you can call Numbers_Words::toWords() with just a string.

The following languages are supported (in alphabetical order):
- bg (Bulgarian) by Kouber Saparev
- de (German)
- ee (Estonian) by Erkki Saarniit
- en_100 (Donald Knuth system, English)
- en_GB (Britich English)
- en_US (American English)
- es (Spanish Castellano) by Xavier Noguer
- es_AR (Argentinian Spanish) by Martin Marrese
- fr (French) by Kouber Saparev
- id (Indonesian) by Ernas M. Jamil
- it_IT (Italian) by Filippo Beltramini and Davide Caironi
- pl (Polish)
- pt_BR (Brazilian Portuguese) by Marcelo Subtil Marcal
- ru (Russian) by Andrey Demenev
- sv (Swedish) by Robin Ericsson