- added unit tests for Enigma2 and Grundig loaders

- added round-trip unit test for all loaders to check reordering channels and favorites, saving and reloading
- internal code clean-up regarding different favorite list modes (none vs. flags vs. ordered per source vs. mixed source)

source/Test.Api/ReferenceListTest.cs

@@ -0,0 +1,16 @@
+using Microsoft.VisualStudio.TestTools.UnitTesting;
+using System;
+using ChanSort.Api;
+
+namespace Test.Api
+{
+  [TestClass]
+  public class ReferenceListTest
+  {
+    [TestMethod]
+    public void TestMethod1()
+    {
+
+    }
+  }
+}