The harvest_source_delete logic function proxies to package delete,
which will delete the harvest source dataset. The harvest plugin then
hooks to the after_delete extension point in order to inactivate the
actual HarvestSource object and abort any pending jobs.
Also added the Delete button to the harvest source form.
The first version of the auth layer is based on the current policy, i.e.
you need to be sysadmin to perform any action.
TODO: the CLI is still not working.
amercader
David Read