title: How to create a placeholder for a specific plugin in django-cms 3.0.0
body: <p>How do i create a placeholder that can only be filled with a specific plugin?
  I'd like to create a template in <strong>django-cms 3.0.0.beta2</strong>, with a placeholder only for the pictures plugin. I couldn't find any option in the docs.</p>
  
  <p><a href="http://django-cms.readthedocs.org/en/develop/advanced/templatetags.html" rel="noreferrer">http://django-cms.readthedocs.org/en/develop/advanced/templatetags.html</a></p>