ATM Validity Period

[cos-it-is]

Add the ability to set a validity period for invoices created by an ATM device. This is good for turning the ATM into a gift voucher dispenser to provide to friends/families for redemption at a later day. IMO configurable in day periods from 1-365 (or weeks, months selectors) - but not DATETIME as devices wont have NTP time functions when creating.