title: Profile GUI application bootstrap
body: <p>I have some applications which suffer of very slow boot time.</p>
  
  <p>In theory I just want to exit as soon as the gui fires up. Until now I've done it by hand, and it worked, but I wonder if there is a better way...</p>
  
  <p>A solution of course would be to add a "sys.exit" where I want to make it quit, but I should modify the code then.</p>
  
  <p>Is there a way to instrument the file to quit on some conditions without modifying it?</p>