added marr.datamapper source code for easy debugging.

Marr.Data/QGen/IQuery.cs

@@ -0,0 +1,16 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+
+namespace Marr.Data.QGen
+{
+    internal interface IQuery
+    {
+        /// <summary>
+        /// Generates a SQL query for a given entity.
+        /// </summary>
+        /// <returns></returns>
+        string Generate();
+    }
+}