Nuxeo Studio should warn about unknown permission IDs.

• In structure templates
• In automation chains for permission related operations:
  => Document.AddPermission:
  => Document.ReplacePermission:
  => Document.AddACE:
  => Context.GetEmailsWithPermissionOnDoc:
  => Context.GetUsersGroupIdsWithPermissionOnDoc:

When a permission is defined in the corresponding parameter and the permission is not found:

• in the default permissions list,
• in the permissions feature,
• or in the registries,
  Studio should show a warning with the following text:

  The permission PERMISSION-NAME does not seem to exist.
  Custom permissions can be created using the Roles & Permissions / Permissions feature, or declared in the Registries feature if you created them using an XML extension.