APS450 Poland: Add amount in words for self-billing invoices
The requirement for Poland to present the amount in words for self-billing invoices (APS456PF) is now addressed. Functionalities for other types of invoices exist and those routines are used to solve this requirement. The standard language is used for any other document language rather than 'PL' as default for the Polish version of this print file. Also, the standard version now has the same fields available as amounts to word according to the existing standard used for other invoices.