Initial commit of changes for 1.2.3. This includes:

- Scripting support: Allows for recording and playback of mouse/keyboard input and various system control actions.  Simple (i.e. basic) scripting format.

- Fix for stale packets left in ethernet input queue; packets received by pcap while Alto's receiver is off are discarded.

- Mouse input made more accurate, and tweaked to avoid Alto microcode bug that causes erroneous mouse inputs under very rare circumstances on real hardware, but much more frequently under emulation.

- Small code cleanup here and there.  Moved many UI strings to resources, many more to go.

Contralto/Scripting/ScriptWriter.cs

@@ -0,0 +1,42 @@
+using System;
+using System.Collections.Generic;
+using System.IO;
+using System.Linq;
+using System.Text;
+using System.Threading.Tasks;
+
+namespace Contralto.Scripting
+{
+    /// <summary>
+    /// 
+    /// </summary>
+    public class ScriptWriter
+    {
+        public ScriptWriter(string scriptPath)
+        {
+            _scriptWriter = new StreamWriter(scriptPath);
+        }
+
+        /// <summary>
+        /// Adds a new ScriptAction to the queue
+        /// </summary>
+        /// <param name="action"></param>
+        public void AppendAction(ScriptAction action)
+        {
+            if (_scriptWriter == null)
+            {
+                throw new InvalidOperationException("Cannot write to closed ScriptWriter.");
+            }
+
+            _scriptWriter.WriteLine(action.ToString());
+        }
+
+        public void End()
+        {
+            _scriptWriter.Close();
+            _scriptWriter = null;
+        }
+
+        private StreamWriter _scriptWriter;
+    }
+}