Issue: #336: Split "Administer comments"

Fixes issue #336. Assumes persons with "administer comments" permission should also be able to "administer comment settings" but not the reverse.
I imagined "administer comment settings" as the mere moderators, and "administer comments" as the admins. My way, admins get access to evrything comment-related including settings, moderators can only set settings. Your suggestion leaves the option for a person to have access to everything else comment-related but be unable to set settings, which seems counter-intuitive.
Or do you see 'administer comment settings' as the higher permission? is it that you want 'moderators' to only have access to the operations at '/admin/content/comment'? (view, edit, delete)