add promise

+var $ = require('yoho-jquery');
+
+$.extend({
+    defer: function(func) {
+        return function() {
+            var defer = $.Deferred(); // eslint-disable-line
+            var args = Array.prototype.slice.call(arguments);
+
+            args.push(defer.resolve, defer.reject);
+            func && func.apply(undefined, args);
+            return defer.promise();
+        };
+    },
+    reject: function() {
+        var defer = $.Deferred(); // eslint-disable-line
+        var args = Array.prototype.slice.call(arguments);
+
+        return defer.reject.apply(defer, args).promise();
+    },
+    resolve: function() {
+        var defer = $.Deferred(); // eslint-disable-line
+        var args = Array.prototype.slice.call(arguments);
+
+        return defer.resolve.apply(defer, args).promise();
+    }
+});