Fix Wox restart

1. refactoring restart
2. delte some windows forms methods
3. using string inteperlation and delete hard coeded new line char

should fix #322

Wox/App.xaml.cs

@@ -52,6 +52,10 @@ namespace Wox
 
         public bool OnActivate(IList<string> args)
         {
+            if (args.Count > 0 && args[0] == SingleInstance<App>.Restart)
+            {
+                Window.CloseApp();
+            }
             CommandArgsFactory.Execute(args);
             return true;
         }