+ only adds an optional parameter to url() and l(), so individual links
    can be set to be absolute
  + modifies drupal_goto() to accept the parameters of url() without the
    $absolute parameter, so cleaner invocations can be used
  + rework of some code in node_feed, making it much better to look at
    (the current code uses foreach with an immediate brake to get the first
    key of the associative array, geeeeez)
  + added xml:base to the rss tag generated by node_feed()
  + set all user mail URLs to be absolute
  + fix a small fragmented URL in user.module