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/httpget/src/httpget.cpp

@@ -0,0 +1,94 @@
+//
+// httpget.cpp
+//
+// This sample demonstrates the HTTPClientSession and the HTTPCredentials classes.
+//
+// Copyright (c) 2005-2012, Applied Informatics Software Engineering GmbH.
+// and Contributors.
+//
+// SPDX-License-Identifier:	BSL-1.0
+//
+
+
+#include "Poco/Net/HTTPClientSession.h"
+#include "Poco/Net/HTTPRequest.h"
+#include "Poco/Net/HTTPResponse.h"
+#include "Poco/Net/HTTPCredentials.h"
+#include "Poco/StreamCopier.h"
+#include "Poco/NullStream.h"
+#include "Poco/Path.h"
+#include "Poco/URI.h"
+#include "Poco/Exception.h"
+#include <iostream>
+
+
+using Poco::Net::HTTPClientSession;
+using Poco::Net::HTTPRequest;
+using Poco::Net::HTTPResponse;
+using Poco::Net::HTTPMessage;
+using Poco::StreamCopier;
+using Poco::Path;
+using Poco::URI;
+using Poco::Exception;
+
+
+bool doRequest(Poco::Net::HTTPClientSession& session, Poco::Net::HTTPRequest& request, Poco::Net::HTTPResponse& response)
+{
+	session.sendRequest(request);
+	std::istream& rs = session.receiveResponse(response);
+	std::cout << response.getStatus() << " " << response.getReason() << std::endl;
+	if (response.getStatus() != Poco::Net::HTTPResponse::HTTP_UNAUTHORIZED)
+	{
+		StreamCopier::copyStream(rs, std::cout);
+		return true;
+	}
+	else
+	{
+		Poco::NullOutputStream null;
+		StreamCopier::copyStream(rs, null);
+		return false;
+	}
+}
+
+
+int main(int argc, char** argv)
+{
+	if (argc != 2)
+	{
+		Path p(argv[0]);
+		std::cout << "usage: " << p.getBaseName() << " <uri>" << std::endl;
+		std::cout << "       fetches the resource identified by <uri> and print it to the standard output" << std::endl;
+		return 1;
+	}
+
+	try
+	{
+		URI uri(argv[1]);
+		std::string path(uri.getPathAndQuery());
+		if (path.empty()) path = "/";
+
+		std::string username;
+		std::string password;
+		Poco::Net::HTTPCredentials::extractCredentials(uri, username, password);
+		Poco::Net::HTTPCredentials credentials(username, password);
+
+		HTTPClientSession session(uri.getHost(), uri.getPort());
+		HTTPRequest request(HTTPRequest::HTTP_GET, path, HTTPMessage::HTTP_1_1);
+		HTTPResponse response;
+		if (!doRequest(session, request, response))
+		{
+			credentials.authenticate(request, response);
+			if (!doRequest(session, request, response))
+			{
+				std::cerr << "Invalid username or password" << std::endl;
+				return 1;
+			}
+		}
+	}
+	catch (Exception& exc)
+	{
+		std::cerr << exc.displayText() << std::endl;
+		return 1;
+	}
+	return 0;
+}