Add RIGS hyperlink to assets header. Closes #367.

I'd rather have it further over, but that breaks out of the navbar, and I don't want to move the assets links more right...

templates/base_assets.html

@@ -1,6 +1,7 @@
 {% extends 'base.html' %}
 {% block titleheader %}
-    <a class="navbar-brand" href="{% url 'asset_index' %}">Assets</a>
+    <a class="nav navbar-brand navbar-left" href="/"><i class="glyphicon glyphicon-circle-arrow-left" style="vertical-align: middle !important;"></i> RIGS</a>
+    <a class="nav navbar-brand" href="{% url 'asset_index' %}">Assets</a>
 {% endblock %}
 
 {% block titleelements %}
@@ -27,4 +28,4 @@
             </ul>
         </li>
     {% endif %}
-{% endblock %}
+{% endblock %}