convert all icons to font-awesome vector based / retina compatible icons

data/interfaces/default/shutdown.html

@@ -7,7 +7,7 @@
 <%def name="body()">
 	<div class="table_wrapper">
 		<div id="shutdown">
-		<h1><img src="interfaces/default/images/loader_black.gif"/> Headphones is ${message}</h1>
+		<h1><i class="fa fa-refresh fa-spin"></i>  Headphones is ${message}</h1>
 		</div>
 	</div>
 </%def>