I've got a wiki that is built at two places:

* a static copy, aimed at being viewed without any web server, using
  a web browser's `file:///` urls => usedirs is disabled to get nice
  and working links
* an online copy, with usedirs enabled in order to benefit from the
  language negotiation using the po plugin

I need to use mirrorlist on the static copy, so that one can easily
reach the online, possibly updated, pages. But as documented, "pages are
assumed to exist in the same location under the specified url on each
mirror", so the generated urls are wrong.

My `mirrorlist` branch contains a patch that allows one to configure usedirs
per-mirror. Note: the old configuration format is still supported, so this should
not break existing wikis.

OT: as a bonus, this branch contains a patch to support {hashes,arrays} of
{hashes,arrays} in `$config`, which I missed a bit when writing the po plugin,
and decided this time it was really needed to implement this feature.

--[[intrigeri]]

[[!tag patch]]
