updated option handling for manipulation system

examples/network/01_basic_usage.html

@@ -53,6 +53,9 @@
                   data.label = data.label + "i"
                   callback(data)
               }
+          },
+          controlNodeStyle: {
+              shape:'square'
           }
       }}//{physics:{stabilization:false}};
   var network = new vis.Network(container, data, options);

lib/network/modules/ManipulationSystem.js

@@ -74,11 +74,7 @@ class ManipulationSystem {
       }
       else {
         this.options.enabled = true;
-        for (let prop in options) {
-          if (options.hasOwnProperty(prop)) {
-            this.options[prop] = options[prop];
-          }
-        }
+        util.deepExtend(this.options, options);
       }
       if (this.options.initiallyVisible === true) {
         this.editMode = true;