* errors, specially during long initial runs are caught better now and should continue, if possible
* set `SKIP_EXISTING_DOCS` to `true` (default) to skip existing documents (if set to false, they won't be uploaded again, but tags, correspondent, date and title will be overwritten)
* for testing purposes you can set the variables `LIMIT` and `LIMIT_DOC` to limit the tags and correspondents respetively the documents and document-tag-relations
