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/Foundation/include/Poco/NullChannel.h

@@ -0,0 +1,57 @@
+//
+// NullChannel.h
+//
+// Library: Foundation
+// Package: Logging
+// Module:  NullChannel
+//
+// Definition of the NullChannel class.
+//
+// Copyright (c) 2004-2006, Applied Informatics Software Engineering GmbH.
+// and Contributors.
+//
+// SPDX-License-Identifier:	BSL-1.0
+//
+
+
+#ifndef Foundation_NullChannel_INCLUDED
+#define Foundation_NullChannel_INCLUDED
+
+
+#include "Poco/Foundation.h"
+#include "Poco/Channel.h"
+
+
+namespace Poco {
+
+
+class Foundation_API NullChannel: public Channel
+	/// The NullChannel is the /dev/null of Channels.
+	///
+	/// A NullChannel discards all information sent to it.
+	/// Furthermore, its setProperty() method ignores 
+	/// all properties, so it the NullChannel has the
+	/// nice feature that it can stand in for any
+	/// other channel class in a logging configuration.
+{
+public:
+	using Ptr = AutoPtr<NullChannel>;
+
+	NullChannel();
+		/// Creates the NullChannel.
+
+	~NullChannel();
+		/// Destroys the NullChannel.
+
+	void log(const Message& msg);
+		/// Does nothing.
+
+	void setProperty(const std::string& name, const std::string& value);
+		/// Ignores both name and value.
+};
+
+
+} // namespace Poco
+
+
+#endif // Foundation_NullChannel_INCLUDED