fix issues copy past on mac (nodewebkit)

app.js

var nw = require('nw.gui');

var win = nw.Window.get();
var nativeMenuBar = new nw.Menu({ type: "menubar" });

if (nativeMenuBar.createMacBuiltin) {
  nativeMenuBar.createMacBuiltin("User-factory");
}

win.menu = nativeMenuBar;