Major plugin refactor and cleanup.

Switched to POCO library for unified platform/library interface.
Deprecated the external module API. It was creating more problems than solving.
Removed most built-in libraries in favor of system libraries for easier maintenance.
Cleaned and secured code with help from static analyzers.

vendor/POCO/Util/src/Subsystem.cpp

@@ -0,0 +1,44 @@
+//
+// Subsystem.cpp
+//
+// Library: Util
+// Package: Application
+// Module:  Subsystem
+//
+// Copyright (c) 2004-2006, Applied Informatics Software Engineering GmbH.
+// and Contributors.
+//
+// SPDX-License-Identifier:	BSL-1.0
+//
+
+
+#include "Poco/Util/Subsystem.h"
+
+
+namespace Poco {
+namespace Util {
+
+
+Subsystem::Subsystem()
+{
+}
+
+
+Subsystem::~Subsystem()
+{
+}
+
+
+void Subsystem::reinitialize(Application& app)
+{
+	uninitialize();
+	initialize(app);
+}
+
+
+void Subsystem::defineOptions(OptionSet& options)
+{
+}
+
+
+} } // namespace Poco::Util