WebUI : add "pointer" cursor for sortable column

glances/outputs/static/css/style.css

@@ -36,6 +36,9 @@ body {
     font-weight: bold;
     color: white;
 }
+.sortable {
+    cursor: pointer;
+}
 .text-right {
     text-align: right;
 }

glances/outputs/static/js/directives.js

@@ -6,6 +6,8 @@ glancesApp.directive("sortableTh", function() {
         },
         link: function (scope, element, attrs) {
 
+            element.addClass('sortable');
+
             scope.$watch(function() {
                 return scope.sorter.column;
             }, function(newValue, oldValue) {