Erply API version 1.17.1

Fixes

• Fixed: when re-saving a sales or purchase document with API calls saveSalesDocument
   or savePurchaseDocument
  , and only updating/setting an attribute or some other field (without updating document rows), package quantities on rows were lost.
• Fixed: when re-saving a sales document with API call saveSalesDocument
  , the "Billing period" information on invoice (start and end date) was lost.
• Fixed: API calls saveProductGroup
   and saveProductCategory
   no longer allow to set a group as its own parent.
• Fixed: API call saveSalesDocument
   returned an error when saving a receipt with promotion information and a manual discount.
• Fixed: API call getProductStock
   returned an error when using input parameters "getProductsWithReorderPointDefined" = 1 or "getProductsWithRestockLevelDefined" = 1.