version=3
  opts="uversionmangle=s/(?=[^\.\d]+(?:\d+)?)$/\~/;s/0(\d)/0.$1/g" \
  http://releases.mozilla.org/pub/mozilla.org/addons/1843/ \
    firebug-(\d+(?:\.\d+){1,3}(?:\w+\d+)?).*\.xpi
