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.

With the Numbers_Words::toCurrency($num, $locale, 'USD') method
you can convert a number (decimal and fraction part) to words with currency
name.

The following languages are supported:
* bg (Bulgarian) by Kouber Saparev
* cs (Czech) by Petr 'PePa' Pavel
* de (German) by Piotr Klaban
* dk (Danish) by Jesper Veggerby
* en_100 (Donald Knuth system, English) by Piotr Klaban
* en_GB (British English) by Piotr Klaban
* en_US (American English) by Piotr Klaban
* es (Spanish Castellano) by Xavier Noguer
* es_AR (Argentinian Spanish) by Martin Marrese
* et (Estonian) by Erkki Saarniit
* fr (French) by Kouber Saparev
* fr_BE (French Belgium) by Kouber Saparev and Philippe Bajoit
* he (Hebrew) by Hadar Porat
* hu_HU (Hungarian) by Nils Homp
* id (Indonesian) by Ernas M. Jamil and Arif Rifai Dwiyanto
* it_IT (Italian) by Filippo Beltramini and Davide Caironi
* lt (Lithuanian) by Laurynas Butkus
* nl (Dutch) by WHAM van Dinter
* pl (Polish) by Piotr Klaban
* pt_BR (Brazilian Portuguese) by Marcelo Subtil Marcal and Mario H.C.T.
* ru (Russian) by Andrey Demenev
* sv (Swedish) by Robin Ericsson