allowed admin to remove skins, if set

src/views/admin/partials/theme_list.tpl

@@ -3,7 +3,7 @@
 	<img title="{themes.id}" src="{themes.screenshot_url}" />
 	<div>
 		<div class="pull-right">
-		<button class="btn btn-primary" data-action="use">Use</button>
+			<button class="btn btn-primary" data-action="use">Use</button>
 		</div>
 		<h4>{themes.name}</h4>
 		<p>
@@ -15,4 +15,11 @@
 	</div>
 	<div class="clear"></div>
 </li>
-<!-- END themes -->
+<!-- END themes -->
+<li data-type="bootswatch" data-theme="" data-css="">
+	<div class="pull-right">
+		<button class="btn btn-primary pull-right" data-action="use">Revert</button>
+	</div>
+	<h4>No Skin</h4>
+	<p>Remove applied skin and revert back to the base colours</p>
+</li>