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/NetSSL_OpenSSL/include/Poco/Net/Session.h

@@ -0,0 +1,79 @@
+//
+// Session.h
+//
+// Library: NetSSL_OpenSSL
+// Package: SSLCore
+// Module:  Session
+//
+// Definition of the Session class.
+//
+// Copyright (c) 2010, Applied Informatics Software Engineering GmbH.
+// and Contributors.
+//
+// SPDX-License-Identifier:	BSL-1.0
+//
+
+
+#ifndef NetSSL_Session_INCLUDED
+#define NetSSL_Session_INCLUDED
+
+
+#include "Poco/Net/NetSSL.h"
+#include "Poco/RefCountedObject.h"
+#include "Poco/AutoPtr.h"
+#include <openssl/ssl.h>
+
+
+namespace Poco {
+namespace Net {
+
+
+class NetSSL_API Session: public Poco::RefCountedObject
+	/// This class encapsulates a SSL session object
+	/// used with session caching on the client side.
+	///
+	/// For session caching to work, a client must
+	/// save the session object from an existing connection,
+	/// if it wants to reuse it with a future connection.
+{
+public:
+	using Ptr = Poco::AutoPtr<Session>;
+
+	SSL_SESSION* sslSession() const;
+		/// Returns the stored OpenSSL SSL_SESSION object.
+
+protected:
+	Session(SSL_SESSION* pSession);
+		/// Creates a new Session object, using the given
+		/// SSL_SESSION object.
+		///
+		/// The SSL_SESSION's reference count is not changed.
+
+	~Session();
+		/// Destroys the Session.
+		///
+		/// Calls SSL_SESSION_free() on the stored
+		/// SSL_SESSION object.
+
+private:
+	Session();
+
+	SSL_SESSION* _pSession;
+
+	friend class SecureSocketImpl;
+};
+
+
+//
+// inlines
+//
+inline SSL_SESSION* Session::sslSession() const
+{
+	return _pSession;
+}
+
+
+} } // namespace Poco::Net
+
+
+#endif // NetSSL_Session_INCLUDED