Add parameters to InvoicePrint process

@Carlos Ruiz,

attached you can find a new patch for peer review.

Kind Regards,
Diego Ruiz
BX Service GmbH

I like to add some more parameters:

• IsPrinted - allows to print invoices inbetween the daily work but not print double invoices

• PaymentRule - allows to not print cash invoices because they are already paid (at pos or during delivery or so)

• PaymentTerm allows to print Invoices for customers with special payment terms in a different batch to do different things with them

• DocStatus - is an idea of Carlos Ruiz, can be added without harm and allows to fit into different company's workflows

• Another idea for my own business case is to sort or filter invoices by an "invoice dispatch way" that allows to separate invoices to be sent by email, post mail, own delivery or different post services. I am not yet sure how that can be done the best way in iDempiere.

Carlos Ruiz suggested to set the IsPrint status only for completed documents.

@Carlos Ruiz,

attached you can find the patch for peer review.

Kind Regards,
Diego Ruiz