MAGETWO-38867: Create mixin for declarative widget description

Author: Ihor Melnychenko

lib/web/mage/apply/main.js

@@ -44,10 +44,11 @@ define([
 
         _.each(mixins, function (mixin, componentName) {
             configStack = itemContainer.data[componentName];
-            _.each(mixin, function (item) {
-                require([item], function (fn) {
-                    configStack = fn(configStack, element);
-                });
+            require(mixin, function(){
+                for (var i = 0, l = arguments.length; i < l; i++){
+                    configStack = arguments[i](configStack, element);
+                }
+
             });
             itemContainer.data[componentName] = configStack;
         });