Implemented AbortSlew and did some code tidy up.

MeadeAutostar497/Controller/ITelescopeController.cs

@@ -1,15 +1,14 @@
 using System;
-using System.IO.Ports;
 
 namespace ASCOM.MeadeAutostar497.Controller
 {
     public interface ITelescopeController
     {
-        ISerialProcessor SerialPort { get; set; }
         string Port { get; set; }
         bool Connected { get; set; }
 
         bool Slewing { get; }
         DateTime utcDate { get; set; }
+        void AbortSlew();
     }
 }