Newsletter section on My Account page should appear only if user has appropriate access

If a role is configured to not have the subscribe/unsubscribe permission for newsletters, then the newsletter section should not appear on the My Account page for users in such roles.

Current behavior is the section appears, but when you click on the "my newsletters" link, you get an empty page with a single submit button, which will confuse users.

Better for this section to appear only for users in roles that actually have the subscribe/unsubscribe permission.

In my case, I'm restricting access to newsletters while we're trying out the module. I'd prefer for newsletters to be completely invisible to general users until we've decided how to use the module, ran a few tests, and set up our newsletters.