For #242, move the updating of the POTD sequence into a new signals module. When photos are deleted from the admin changelist in bulk, the individual delete() functions on the photo objects is not called. However, the post_delete signal is called for each object.

{% load url from future %}
{% if show_button %}
<a href="{% url 'forums-edit_post' id=post.id %}"><img src="{{ STATIC_URL }}icons/page_edit.png" alt="Edit post" title="Edit post" /></a>
{% endif %}