Division by zero when calculating shipping tax rate

Fixed #42 
allow to print creditmemos with no items
Unified invoice and creditmemo item rendering
Merge pull request #40 from NetresearchAppFactory/development

fixes #38: update call to footer method
Merge pull request #43 from sprankhub/creditmemo-patch

Allow to print creditmemos with no items
Merge pull request #44 from sprankhub/creditmemo-patch2

Unified invoice and creditmemo item rendering
Fix shipment and creditmemo creation, refactoring
Merge pull request #45 from sprankhub/refactoring

Fix shipment and creditmemo creation, refactoring
Added notes to shipment and credit memo, added missing translations
Merge pull request #46 from sprankhub/notes2

Added notes to shipment and credit memo, added missing translations
#33: Add shipment bundle item renderer.
Fix wrong translation for quantity on packing slip.
Remove creditmemo item renderer. Invoice item renderer is used instead.
#21: Print shipping method and order id on invoice.