gistfile1.js

$(function() {
  setInterval(function() {
    $(".reloadable").each(function(i) {
      originalSrc = $(this).data('originalSrc');
      if (!originalSrc) {
        originalSrc = $(this).attr('src');
        $(this).data('originalSrc', originalSrc);
      }
      $(this).attr('src', originalSrc + '&hack=' + new Date().getTime());
    });
  }, 300000);
});