[#51] Update dataset update API endpoints
[#39] Wrap API calls in try/except and update task

Otherwise the task kept the 'new' value, preventing users from using the
same dataset name.
[#42] Don't allow datasets with the same title within the same org

If you really want it, CKAN can do it for you.
[#42] Check title uniqueness among pending datasets

Check if a pending request for dataset creation has the same title
within the same org.