how to replace an existing document : the following batch doesnt' give agood result (documents are skipped !) :
curl -v -u admin:admin -L POST --url "localhost:8080/alfresco/s/bulkfsimport/initiate" --data "targetPath=/Sites/courrier-retraite/documentLibrary/Plis Retraite&sourceDirectory=C:\alfresco\Documents\123456789&replaceExisting=true"