Implemented AbortSlew and did some code tidy up.

MeadeAutostar497/Controller/ISerialProcessor.cs

@@ -0,0 +1,26 @@
+using System.IO.Ports;
+using System.Runtime.InteropServices;
+
+namespace ASCOM.MeadeAutostar497.Controller
+{
+    [ComVisible(false)]
+    public interface ISerialProcessor
+    {
+        bool IsOpen { get; }
+        bool DtrEnable { get; set; }
+        bool RtsEnable { get; set; }
+        int BaudRate { get; set; }
+        int DataBits { get; set; }
+        StopBits StopBits { get; set; }
+        Parity Parity { get; set; }
+        string PortName { get; set; }
+        string[]  GetPortNames();
+        void Open();
+        void Close();
+
+        string CommandTerminated(string command, string terminator);
+        char CommandChar(string command);
+        string ReadTerminated(string terminator);
+        void Command(string command);
+    }
+}