add subsection edit page to the project with a shared 'unit' widget that will…

add subsection edit page to the project with a shared 'unit' widget that will render out unit lists. Both edit_subsection and overview.html will share this widget

cms/templates/widgets/units.html

+<%! from django.core.urlresolvers import reverse %>
+
+<!--
+This def will enumerate through a passed in subsection and list all of the units
+-->
+<%def name="enum_units(subsection)">
+<ol>
+  % for unit in subsection.get_children():
+  <li class="leaf">
+    <div class="section-item">
+      <a href="${reverse('edit_unit', args=[unit.location])}" class="private-item">
+	<span class="${unit.category}-icon"></span>${unit.display_name} <span class="private-tag">- private</span>
+      </a>
+      <div class="item-actions">
+	<a href="${reverse('delete_unit', args=[unit.location])}" classs="edit-button wip"><span class="delete-icon"></span></a>
+	<a href="#" class="drag-handle wip"></a>
+      </div>
+    </div>
+  </li>
+  % endfor
+  <li>
+    <a href="#" class="new-unit-item wip">
+      <span class="new-unit-icon"></span>New Unit
+    </a>
+  </li>
+</ol>
+</%def>