When using the search plugin, results are linked to `foo/bar/index.html`,
whether or not use_dirs is enabled; when use_dirs is enabled, the link should
point to `foo/bar/` instead.

> Similarly, after editing a page `foo/bar/`, the user is redirected to
> `foo/bar/index.html?updated` instead of `foo/bar/?updated`.
> --[Jason Blevins](http://jblevins.org/)

>> Even with `usedirs`, there is no reason why the `index.html` should be called directly, and it might break content negotiation. Please just direct to the directory. --[[madduck]]

> This bug affects the [[plugins/amazon_s3]] plugin -- when using that
> plugin plus the search plugin, you need to enable `amazon_s3_dupindex`.
> So this definitly should be fixed. --[[Joey]]

> [[done]], the new xapian search uses nice urls
