Refactoring. Move system plugins to seperate DLLs.

Wox.Core/UI/IUIResource.cs

@@ -0,0 +1,16 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+using System.Windows;
+
+namespace Wox.Core.UI
+{
+    /// <summary>
+    /// Object implement this interface will have the ability to has its own UI styles
+    /// </summary>
+    interface IUIResource
+    {
+        ResourceDictionary GetResourceDictionary();
+    }
+}