Log Message:
Update to 3.20121016. From the changelog:

   * monochrome: New theme, contributed by Jon Dowland.
   * rst: Ported to python 3, while still also being valid python 2.
     Thanks, W. Trevor King
   * Try to avoid a situation in which so many ikiwiki cgi wrapper programs
     are running, all waiting on some long-running thing like a site rebuild,
     that it prevents the web server from doing anything else. The current
     approach only avoids this problem for GET requests; if multiple cgi's
     run GETs on a site at the same time, one will display a "please wait"
     page for a configurable number of seconds, which then redirects to retry.
     To enable this protection, set cgi_overload_delay to the number of
     seconds to wait. This is not enabled by default.
   * Add back a 1em margin between archivepage divs.
   * recentchangesdiff: Correct broken template that resulted in duplicate
     diff icons being displayed, and bloated the recentchanges page with
     inline diffs when the configuration should have not allowed them.