* Plugins can add new directories to the search path with the add_underlay
function.
* Split out smiley underlay files into a separate underlay, so if the plugin
isn't used, the wiki isn't bloated with all those files.
patches can now be anywhere and tagged patch to show up on the patch list.
Moved all the patchqueue stuff to todo items; some of it was merged into
existing todo items.
joey