title: Django logs out when dev server restarts
body: <p>While developing a Django 1.8 project, I am logged out each time the dev server restarts. That means each time the python code is changed (and the dev server restarts) I have to log back in. It's driving me slightly crazy.</p>
  
  <p>I am using the default <code>SESSION_ENGINE</code> i.e. <code>django.contrib.sessions.backends.db</code> and can see the <code>django_session</code> table has values.</p>
  
  <p>I have <code>DEBUG=True</code> on.</p>
  
  <p>Can anyone suggest other things to check? Thanks.</p>