Removal of "Add Child Page" link and "Outline" tab if update permission is not granted on the book

Thanks for this, I've modified this patch to "fix" the "Add child page" link display for D5 with a slightly simplified version.

The patch should be created for the development snapshot.

The patch as it is doesn't follow the coding standards; then, the code that changes the access callback of the menu should also change the access arguments.

The development snapshot already has the code to remove the link Add child page; therefore that part of the patch is not necessary.

      $bool = (
       $grant_update &&          (
          user_access('add content to books') ||
          user_access('administer book outlines')
        ) &&
        node_access('create', variable_get('book_child_type', 'book')) &&
        $node->status == 1 &&
        $node->book['depth'] < MENU_MAX_DEPTH
      );

      if (!$bool) {
        // Remove the link "add child page".
        unset($node->links['book_add_child']);
      }
      break;

I started to change the code added by the patch, and applying it in chunks.
For now, I moved the code that was in hook_nodeapi() into hook_menu_link_alter(); I also updated the code that verifies if the user has the permission to update the book as granted by the realm book_access_rule.

I added the rest of the code, after I changed it to follow more the coding standards, and after I fixed the code (removing a book page from a book doesn't mean to delete it).

Thanks for the report, and the help with the code.