added better db migration support than what Subsonic provides out of the box.

Migrator.net/Migrator.Framework/IMigration.cs

@@ -0,0 +1,39 @@
+namespace Migrator.Framework
+{
+    public interface IMigration
+    {
+        string Name { get; }
+
+        /// <summary>
+        /// Represents the database.
+        /// <see cref="ITransformationProvider"></see>.
+        /// </summary>
+        /// <seealso cref="ITransformationProvider">Migration.Framework.ITransformationProvider</seealso>
+        ITransformationProvider Database { get; set; }
+
+        /// <summary>
+        /// Defines tranformations to port the database to the current version.
+        /// </summary>
+        void Up();
+
+        /// <summary>
+        /// This is run after the Up transaction has been committed
+        /// </summary>
+        void AfterUp();
+
+        /// <summary>
+        /// Defines transformations to revert things done in <c>Up</c>.
+        /// </summary>
+        void Down();
+
+        /// <summary>
+        /// This is run after the Down transaction has been committed
+        /// </summary>
+        void AfterDown();
+
+        /// <summary>
+        /// This gets called once on the first migration object.
+        /// </summary>
+        void InitializeOnce(string[] args);
+    }
+}