Add more samples to test the abacus import
It appears that endformat, bindung, Aufwand_A2 and verkaufstext are optional
When importing from Alfresco make sure the meta data is correct

- Fix the meta data for date, identifier, uid and prod:source
- make the params optional when invoking update_xml_with_metadata
If a document is not found by isbn then look it up by title+source_edition