Initial work on an automated VSIX testing tool. Not working or tested yet.

FossilOrigin-Name: 496e4ac984b2548dd5f2f969cd34656b586cfcfe

vsixtest/App.xaml.h

@@ -0,0 +1,27 @@
+//
+// App.xaml.h
+// Declaration of the App class.
+//
+
+#pragma once
+
+#include "App.g.h"
+
+namespace vsixtest
+{
+	/// <summary>
+	/// Provides application-specific behavior to supplement the default Application class.
+	/// </summary>
+	ref class App sealed
+	{
+	protected:
+		virtual void OnLaunched(Windows::ApplicationModel::Activation::LaunchActivatedEventArgs^ e) override;
+
+	internal:
+		App();
+
+	private:
+		void OnSuspending(Platform::Object^ sender, Windows::ApplicationModel::SuspendingEventArgs^ e);
+		void OnNavigationFailed(Platform::Object ^sender, Windows::UI::Xaml::Navigation::NavigationFailedEventArgs ^e);
+	};
+}