add mt-scroll directive to listen scroll event of element

modules/core/client/directives/mt-scroll.client.directive.js

@@ -0,0 +1,23 @@
+(function () {
+  'use strict';
+
+  angular.module('core')
+    .directive('mtScroll', mtScroll);
+
+  function mtScroll() {
+    var directive = {
+      restrict: 'A',
+      link: link
+    };
+
+    return directive;
+
+    function link(scope, element, attrs) {
+      if (attrs.mtScroll) {
+        $(element).on('scroll', function (evt) {
+          scope.$eval(attrs.mtScroll, {$event: event});
+        });
+      }
+    }
+  }
+}());