Group-enabled permissions widget is misleading

The new-style Permissions widget includes the ability to set group-scoped as well as site-scoped permissions.

However in tools which are not group aware (e.g. Polls), this is a bit misleading as it appears to allow you to set different permissions based on group membership, whereas in fact the site permissions are the only permission set consulted.

This probably required a tool config or helper parameter to decide whether to show group-scoped permissions as well as site, or only site permissions.