Add wox plugin installer.

Wox/MainWindow.xaml.cs

@@ -2,6 +2,7 @@
 using System.Collections.Generic;
 using System.IO;
 using System.Linq;
+using System.Runtime.CompilerServices;
 using System.Threading;
 using System.Windows;
 using System.Windows.Controls;
@@ -13,6 +14,7 @@ using WindowsInput.Native;
 using NHotkey;
 using NHotkey.Wpf;
 using Wox.Commands;
+using Wox.Helper;
 using Wox.Infrastructure;
 using Wox.Infrastructure.UserSettings;
 using Wox.Plugin;
@@ -58,6 +60,8 @@ namespace Wox
             }
         }
 
+
+
         public void SetHotkey(string hotkeyStr, EventHandler<HotkeyEventArgs> action)
         {
             var hotkey = new HotkeyModel(hotkeyStr);