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/Error.h

@@ -0,0 +1,52 @@
+//
+// Error.h
+//
+// Library: Foundation
+// Package: Core
+// Module:  Error
+//
+// Definition of the Error class.
+//
+// Copyright (c) 2004-2006, Applied Informatics Software Engineering GmbH.
+// and Contributors.
+//
+// SPDX-License-Identifier:	BSL-1.0
+//
+
+
+#ifndef Foundation_Error_INCLUDED
+#define Foundation_Error_INCLUDED
+
+
+#include "Poco/Foundation.h"
+
+
+namespace Poco {
+
+
+class Foundation_API Error
+	/// The Error class provides utility functions
+	/// for error reporting.
+{
+public:
+
+#ifdef POCO_OS_FAMILY_WINDOWS
+	static DWORD last();
+		/// Utility function returning the last error.
+
+	static std::string getMessage(DWORD errorCode);
+		/// Utility function translating numeric error code to string.
+#else
+	static int last();
+		/// Utility function returning the last error.
+
+	static std::string getMessage(int errorCode);
+		/// Utility function translating numeric error code to string.
+#endif
+};
+
+
+} // namespace Poco
+
+
+#endif // Foundation_Error_INCLUDED