title: Strike through headlines for DONE tasks in Org
body: <p>I'd really like to have my DONE task strikken through in Org-mode. Following the snippet from <a href="http://lists.gnu.org/archive/html/emacs-orgmode/2007-03/msg00179.html">http://lists.gnu.org/archive/html/emacs-orgmode/2007-03/msg00179.html</a> (via Sacha Chua's blog):</p>
  
  <pre><code>(setq org-fontify-done-headline t)
  (custom-set-faces
   '(org-done ((t (:foreground "PaleGreen"
                   :weight normal
                   :strike-through t))))
   '(org-headline-done
              ((((class color) (min-colors 16) (background dark))
                 (:foreground "LightSalmon" :strike-through t)))))
  </code></pre>
  
  <p>This however doesn't work for me (colors are changed but no strike-through). I <em>think</em> it might be due to the solarized theme I use: <a href="https://github.com/sellout/emacs-color-theme-solarized">https://github.com/sellout/emacs-color-theme-solarized</a></p>
  
  <p>Unfortunately I couldn't fix it myself... If I look at <code>customize-face</code> of org-done Strike-through has value "On", but no visual effect.</p>
  
  <p>Thank you very much!</p>