add sorting icons to gridview sort links in basic and advanced app css

web/css/site.css

@@ -18,3 +18,24 @@ body {
 	font-size: 21px;
 	padding: 14px 24px;
 }
+
+/* add sorting icons to gridview sort links */
+a.asc:after, a.desc:after {
+    position: relative;
+    top: 1px;
+    display: inline-block;
+    font-family: 'Glyphicons Halflings';
+    font-style: normal;
+    font-weight: normal;
+    line-height: 1;
+    padding-left: 5px;
+}
+
+a.asc:after  { content: /*"\e113"*/"\e151"; }
+a.desc:after { content: /*"\e114"*/"\e152"; }
+
+.sort-numerical a.asc:after { content: "\e153"; }
+.sort-numerical a.desc:after { content: "\e154"; }
+
+.sort-ordinal a.asc:after { content: "\e155"; }
+.sort-ordinal a.desc:after { content: "\e156"; }