Readded start>end checking. Template improvements

Added descritpions of all error for the user as well as the image.

Added contextual alert boxes for messages in base.

If  start>end start<=>end. Very simple fix, thanks Charlie.

templates/base.html

@@ -110,7 +110,11 @@
                 <div class="info">{{ info }}</div>{% endif %}
             {% if messages %}
                 {% for message in messages %}
-                    <div class="info">{{ message }}</div>
+                    <div class="alert alert-{{ message.level_tag }} alert-dismissible" role="alert">
+                        <button type="button" class="close" data-dismiss="alert" aria-label="Close"><span
+                                aria-hidden="true">&times;</span></button>
+                        {{ message }}
+                    </div>
                 {% endfor %}
             {% endif %}
         {% endblock %}