Mirroring a Book's Heirarchy in a Menu

I submitted a patch to the Auto Menu module today that should allow a book's hierarchy to be automatically updated in a menu structure.

This has the nice side effect of keeping the menu trail active, so if you're looking at a child page of book that happens to be a primary link, for example, that link stays active. It also means the sitemap of the menu is fully generated independent of the book.

Normally I'd use Menu Trails for this sort of thing, but it didn't seem to play nicely with having multiple books as primary link items.