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/NetSSL.h

@@ -0,0 +1,94 @@
+//
+// NetSSL.h
+//
+// Library: NetSSL_OpenSSL
+// Package: SSLCore
+// Module:  OpenSSL
+//
+// Basic definitions for the Poco OpenSSL library.
+// This file must be the first file included by every other OpenSSL
+// header file.
+//
+// Copyright (c) 2006-2009, Applied Informatics Software Engineering GmbH.
+// and Contributors.
+//
+// SPDX-License-Identifier:	BSL-1.0
+//
+
+
+#ifndef NetSSL_NetSSL_INCLUDED
+#define NetSSL_NetSSL_INCLUDED
+
+
+#include "Poco/Net/Net.h"
+#include "Poco/Crypto/Crypto.h"
+
+
+//
+// The following block is the standard way of creating macros which make exporting
+// from a DLL simpler. All files within this DLL are compiled with the NetSSL_EXPORTS
+// symbol defined on the command line. this symbol should not be defined on any project
+// that uses this DLL. This way any other project whose source files include this file see
+// NetSSL_API functions as being imported from a DLL, wheras this DLL sees symbols
+// defined with this macro as being exported.
+//
+#if (defined(_WIN32) || defined(__CYGWIN__)) && defined(POCO_DLL)
+	#if defined(NetSSL_EXPORTS)
+		#define NetSSL_API __declspec(dllexport)
+	#else
+		#define NetSSL_API __declspec(dllimport)
+	#endif
+#endif
+
+
+#if !defined(NetSSL_API)
+	#if !defined(POCO_NO_GCC_API_ATTRIBUTE) && defined (__GNUC__) && (__GNUC__ >= 4)
+		#define NetSSL_API __attribute__ ((visibility ("default")))
+	#else
+		#define NetSSL_API
+	#endif
+#endif
+
+
+//
+// Automatically link NetSSL and OpenSSL libraries.
+//
+#if defined(_MSC_VER)
+	#if !defined(POCO_NO_AUTOMATIC_LIBS)
+		#if !defined(NetSSL_EXPORTS)
+			#pragma comment(lib, "PocoNetSSL" POCO_LIB_SUFFIX)
+		#endif
+	#endif // POCO_NO_AUTOMATIC_LIBS
+#endif
+
+
+namespace Poco {
+namespace Net {
+
+
+void NetSSL_API initializeSSL();
+	/// Initialize the NetSSL library, as well as the underlying OpenSSL
+	/// libraries, by calling Poco::Crypto::OpenSSLInitializer::initialize().
+	///
+	/// Should be called before using any class from the NetSSL library.
+	/// The NetSSL will be initialized automatically, through 
+	/// Poco::Crypto::OpenSSLInitializer instances or similar mechanisms
+	/// when creating Context or SSLManager instances.
+	/// However, it is recommended to call initializeSSL()
+	/// in any case at application startup.
+	///
+	/// Can be called multiple times; however, for every call to
+	/// initializeSSL(), a matching call to uninitializeSSL()
+	/// must be performed.
+	
+
+void NetSSL_API uninitializeSSL();
+	/// Uninitializes the NetSSL library by calling 
+	/// Poco::Crypto::OpenSSLInitializer::uninitialize() and
+	/// shutting down the SSLManager.
+
+
+} } // namespace Poco::Net
+
+
+#endif // NetSSL_NetSSL_INCLUDED