Fix publishers schema

_ignore_missing needs to be after convert_from_extras, remove
unnecessary fields.
No custom fields on publihser form
Rename publisher type field

Otherwise it clashes with the type field of groups and orgs
Fix country list snippet
Add notices for pending and deleted pubs/datasets
Merge branch 'ckan-2.x' of github.com:okfn/ckanext-iati into ckan-2.x