dashboard: make operate template more generic

circle/dashboard/templates/dashboard/operate.html

 {% load i18n %}
 
+{% block question %}
 <p>
 {% blocktrans with obj=object op=op.name %}
 Do you want to do the following operation on {{obj}}:
@@ -7,9 +8,12 @@ Do you want to do the following operation on {{obj}}:
 {% endblocktrans %}
 </p>
 <p class="text-info">{{op.name}}: {{op.description}}</p>
-<div class="pull-right">
+{% endblock %}
 <form method="POST" action="{{url}}">{% csrf_token %}
+  {% block formfields %}{% endblock %}
+  <div class="pull-right">
     <a class="btn btn-default" href="{{object.get_absolute_url}}"
         data-dismiss="modal">{% trans "Cancel" %}</a>
       <button class="btn btn-danger" type="submit">{% if op.icon %}<i class="icon-{{op.icon}}"></i> {% endif %}{{ op|capfirst }}</button>
+  </div>
 </form>