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/OptionCallback.cpp

@@ -0,0 +1,37 @@
+//
+// OptionCallback.cpp
+//
+// Library: Util
+// Package: Options
+// Module:  OptionCallback
+//
+// Copyright (c) 2006, Applied Informatics Software Engineering GmbH.
+// and Contributors.
+//
+// SPDX-License-Identifier:	BSL-1.0
+//
+
+
+#include "Poco/Util/OptionCallback.h"
+
+
+namespace Poco {
+namespace Util {
+
+
+AbstractOptionCallback::AbstractOptionCallback()
+{
+}
+
+
+AbstractOptionCallback::AbstractOptionCallback(const AbstractOptionCallback&)
+{
+}
+
+
+AbstractOptionCallback::~AbstractOptionCallback()
+{
+}
+
+
+} } // namespace Poco::Util