Tryton application platform - account invoice line standalone module

 Tryton is a high-level general purpose application platform. It is the base
 of a complete business solution as well as a comprehensive health and hospital
 information system (GNUHealth).
 .
 This module allows one to create standalone invoice lines that can be added
 later to a draft invoice. The invoice will only accept invoice lines of the
 same type, company, currency and party.