Make adding a child page trigger an e-mail to people subscribed to the parent

Currently the addition of a child page does not trigger a page-change notification to people subscribed to the parent. It would be nice if this could be considered worthy of notification.

• A new page version is not needed, but a special "Child added to page" mail would/could be nice.
• Only the addition of direct child pages should cause a notification to avoid notification insanity.
• Something like this might be a good user option to add - "Consider creation of direct child-pages worthy of change notification"