Log Message:
Update to 3.20130212. From the changelog:

   * htmlscrubber: Allow the bitcoin URI scheme.
   * htmlscrubber: Allow the URI schemes of major VCS's.
   * aggregate: When run with --aggregate, if an aggregation is already
     running, don't go on and --refresh.
   * trail: Avoid excess dependencies between pages in the trail
     and the page defining the trail. Thanks, smcv.
   * opendiscussion: Don't allow editing discussion pages if discussion pages
     are disabled. (smcv)
   * poll: Add expandable option to allow users to easily add new choices to
     a poll.
   * trail: Avoid massive slowdown caused by pagetemplate hook when displaying
     dynamic cgi pages, which cannot use trail anyway.
   * Deal with empty diffurl in configuration.
   * cvs: Various fixes. (schmonz)
   * highlight: Now adds a span with class highlight-<extension> around
     highlighted content, allowing for language-specific css styling.