Update to 3.20100504. From the changelog:

  * Add parameter to displaytime to specify that it is a pubdate,
    and in html5 mode, use time tag.
  * Add placeholder text in search form (in html5 mode only).
  * In html5 mode, use all the nice new semantic tags. Care was taken
    to not change the id/class named used in the CSS, so only CSS
    that refers to tag types needed to be changed.
  * Add ACTIONS variable to page.tmpl, which allows plugins to add arbitrary
    links to the action bar without modifying the template further.
    (COMMENTSLINK and DISCUSSIONLINK could be folded into this, but
    are kept separate for now to avoid breaking modified templates.)
  * websetup: Only display Setup button on admins' preferences page.
  * graphviz: Fix display of preexisting images in preview mode.
  * Fixes a bug in skipping of illegal source files introduced in
    3.20100427.

(schmonz)