Start using start dates for exams

templates/exam_stats.html

@@ -1,7 +1,7 @@
 {% extends 'base.html' %}
 
 {% block content %}
-    <h2>{{exam.name}}: Stats</h2>
+    <h2>{{exam}}: Stats</h2>
     {% if exam.stats_candidates < 4 %}
         Not enough data points...
     {% else %}