* The page name and parent links has switched from using a <h1> to a styled

* The page name and parent links has switched from using a <h1> to a styled
  <span>, so pages can use <h1> internally instead of needing to use <h2>.
* Updated all of ikiwiki's own wiki pages for that.
* Add pagetemplate hook, which can be used by plugins that want to mess
  around with adding new stuff to the page template.
* Remove headercontent; the search plugin now adds the search box to the
  header by registering a pagetemplate hook, and other plugins should do
  similarly.