More refactoring and introduction of further abstractions

Added further tests
Fixed test loading with keyfile only

src/Kp2aUnitTests/TestKp2aApp.cs

@@ -1,5 +1,6 @@
 using System;
 using Android.Content;
+using Android.OS;
 using KeePassLib.Serialization;
 using keepass2android;
 
@@ -50,5 +51,13 @@ namespace Kp2aUnitTests
 		{
 			yesHandler(null, null);
 		}
+
+		public Handler UiThreadHandler {
+			get { return null; } //ensure everything runs in the same thread. Otherwise the OnFinish-callback would run after the test has already finished (with failure)
+		}
+		public IProgressDialog CreateProgressDialog(Context ctx)
+		{
+			return new ProgressDialogStub();
+		}
 	}
 }