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

Migrator.net/Migrator.Providers/ForeignKeyConstraintMapper.cs

@@ -0,0 +1,24 @@
+using Migrator.Framework;
+
+namespace Migrator.Providers
+{
+	public class ForeignKeyConstraintMapper
+	{
+		public string SqlForConstraint(ForeignKeyConstraint constraint)
+		{
+			switch(constraint)
+			{
+				case ForeignKeyConstraint.Cascade:
+                    return "CASCADE";
+				case ForeignKeyConstraint.Restrict:
+                    return "RESTRICT";
+				case ForeignKeyConstraint.SetDefault:
+                    return "SET DEFAULT";
+				case ForeignKeyConstraint.SetNull:
+                    return "SET NULL";
+				default:
+                    return "NO ACTION";
+			}
+		}
+	}
+}