- use ATTACHMENT_CREATE and ATTACHMENT_VIEW
- the checks for ATTACHMENT_VIEW is now done directly in the `list_of_attachments` macro, not in the individual modules
The check for an attachment related permission is done by checking a specific verb against an 'attachmnent'-realm subcontext of the given context, e.g. `'CREATE' in context('attachment').perm`.
An example plugin demonstrating the new mechanism will follow shortly.