Auto-numbering based on weight

It would be nice if the book module automatically numbered nodes in the sub-page list, the next/previous/up links and in the title, according to their weight.

It could either be turned on globally, or per-node with intelligent inheritance.

So for example I create a book page that's already one level into a hierarchy and that has several subpages:

handbook
- hosting an event (creating this node)
--- venue (weight = 0)
--- attendees (weight = 1)
--- food (weight = 3)
--- misc logistics (weight = 10)

When creating the "hosting an event" node I check the auto-numbering option and the following happens:

* The title becomes "1. Hosting an event"
* Any links created by book.module (e.g. in the block and in the sub-page list of the handbook page) are changed to read "1. Hosting an event"

With the sub-pages, if I follow the "add child" link then the auto-numbering option is automatically checked (intelligent inheritance). The book module should then number those nodes accordingly, going by weight/title as it does currently for order. The numbering should be "1.1", "1.2", etc.

Basically the idea is to relieve book authors of the bother of putting those numbers into the title manually, which can be really irksome if you start shuffling the order and have to change the numbering.