title: Delete cookies in Webdriver
body: <p>There is a <code>.delete_all_visible_cookies</code> method in Selenium. I was surprised to discover that <code>.delete_all_cookies</code> in Webdriver is a part of private API thus is not accessible through @driver instance.</p>
  
  <p>It is a problem for IE since it does not start a clean browser on a new test run as FF.</p>