Introduction Java invoicing module

The project has the following objectives: Test, update and go live of an invoicing module developed several years ago, frozen at that time and not yet used productively in Java. The module replaces an outdated, grown software (in use since 1992) as a better maintainable system. A coexistent use of the new modules is planned (example: invoicing with a new system and printing the documents with an old system); additional output of all invoice documents as XML data for downstream print management systems; storage of the recorded selection results for revision-proof searches.