Refactoring. Move plugin related work to Wox.Core

Wox.Core/Exception/WoxCritialException.cs

@@ -0,0 +1,17 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+
+namespace Wox.Core.Exception
+{
+    /// <summary>
+    /// Represent exceptions that wox can't handle and MUST close running Wox.
+    /// </summary>
+    public class WoxCritialException : WoxException
+    {
+        public WoxCritialException(string msg) : base(msg)
+        {
+        }
+    }
+}