event_type can now be specified as column in csv file. If column is not present, default collectives is used.
multiple leaders can now be specified. All columns starting with user_id will be considered for adding leaders. Leaders should be specified as "license_id" or "string(license_id)" or "license_id(string)".
multiple tags can now be specified. All columns starting with tag will be considered for adding tags.
delimiter is now determined with method csv.Sniffer().sniff
Potential retrocompatibility issues:
dictionary keys are now read from first row, thus they need to be specified correctly. Previously they were dictated by app.config["CSV_COLUMNS"] and they needed to have a specific order.
All files that did not contain correct key names in first row will not work after this merge request.
CSV import extensions:
Potential retrocompatibility issues: