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/Net/samples/tcpserver/src/tcpserver.cpp

@@ -0,0 +1,102 @@
+//
+// tcpserver.cpp
+//
+// This sample demonstrates a TCP server.
+//
+// Copyright (c) 2005-2018, Applied Informatics Software Engineering GmbH.
+// and Contributors.
+//
+// SPDX-License-Identifier:	BSL-1.0
+//
+
+
+#include "Poco/Net/TCPServer.h"
+#include "Poco/Net/TCPServerConnection.h"
+#include "Poco/Net/TCPServerConnectionFactory.h"
+#include "Poco/Net/StreamSocket.h"
+#include "Poco/NumberParser.h"
+#include "Poco/Logger.h"
+#include "Poco/Process.h"
+#include "Poco/NamedEvent.h"
+#include <iostream>
+
+
+using Poco::Net::TCPServer;
+using Poco::Net::TCPServerConnectionFilter;
+using Poco::Net::TCPServerConnection;
+using Poco::Net::TCPServerConnectionFactory;
+using Poco::Net::TCPServerConnectionFactoryImpl;
+using Poco::Net::StreamSocket;
+using Poco::UInt16;
+using Poco::NumberParser;
+using Poco::Logger;
+using Poco::Event;
+using Poco::NamedEvent;
+using Poco::Process;
+using Poco::ProcessImpl;
+using Poco::Exception;
+
+
+namespace
+{
+	class ClientConnection: public TCPServerConnection
+	{
+	public:
+		ClientConnection(const StreamSocket& s): TCPServerConnection(s)
+		{
+		}
+
+		void run()
+		{
+			StreamSocket& ss = socket();
+			try
+			{
+				char buffer[256];
+				int n = ss.receiveBytes(buffer, sizeof(buffer));
+				while (n > 0)
+				{
+					std::cout << "Received " << n << " bytes:" << std::endl;
+					std::string msg;
+					Logger::formatDump(msg, buffer, n);
+					std::cout << msg << std::endl;
+					n = ss.receiveBytes(buffer, sizeof(buffer));
+				}
+			}
+			catch (Exception& exc)
+			{
+				std::cerr << "ClientConnection: " << exc.displayText() << std::endl;
+			}
+		}
+	};
+
+	typedef TCPServerConnectionFactoryImpl<ClientConnection> TCPFactory;
+#if defined(POCO_OS_FAMILY_WINDOWS)
+	NamedEvent terminator(ProcessImpl::terminationEventName(Process::id()));
+#else
+	Event terminator;
+#endif
+}
+
+
+int main(int argc, char** argv)
+{
+	try
+	{
+		Poco::UInt16 port = NumberParser::parse((argc > 1) ? argv[1] : "2001");
+
+		TCPServer srv(new TCPFactory(), port);
+		srv.start();
+
+		std::cout << "TCP server listening on port " << port << '.'
+			 << std::endl << "Press Ctrl-C to quit." << std::endl;
+
+		terminator.wait();
+	}
+	catch (Exception& exc)
+	{
+		std::cerr << exc.displayText() << std::endl;
+		return 1;
+	}
+
+	return 0;
+}