add char sort to .net

Signed-off-by: Nikolaj Bjorner <nbjorner@microsoft.com>

src/api/dotnet/CharSort.cs

@@ -0,0 +1,35 @@
+/*++
+Copyright (c) 2016 Microsoft Corporation
+
+Module Name:
+
+    CharSort.cs
+
+Abstract:
+
+    Z3 Managed API: Character Sorts
+
+Author:
+
+    Christoph Wintersteiger (cwinter) 2012-11-23
+
+Notes:
+    
+--*/
+
+using System.Diagnostics;
+using System;
+
+namespace Microsoft.Z3
+{
+    /// <summary>
+    ///  A Character sort
+    /// </summary>
+    public class CharSort : Sort
+    {
+        #region Internal
+        internal CharSort(Context ctx, IntPtr obj) : base(ctx, obj) { Debug.Assert(ctx != null); }
+        internal CharSort(Context ctx) : base(ctx, Native.Z3_mk_char_sort(ctx.nCtx)) { Debug.Assert(ctx != null); }
+        #endregion
+    }
+}