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/MetaProgramming.h

@@ -0,0 +1,144 @@
+//
+// MetaProgramming.h
+//
+// Library: Foundation
+// Package: Core
+// Module:  MetaProgramming
+//
+// Common definitions useful for Meta Template Programming
+//
+// Copyright (c) 2006, Applied Informatics Software Engineering GmbH.
+// and Contributors.
+//
+// SPDX-License-Identifier:	BSL-1.0
+//
+
+
+#ifndef Foundation_MetaProgramming_INCLUDED
+#define Foundation_MetaProgramming_INCLUDED
+
+
+#include "Poco/Foundation.h"
+
+
+namespace Poco {
+
+
+template <typename T>
+struct IsReference
+	/// Use this struct to determine if a template type is a reference.
+{
+	enum
+	{
+		VALUE = 0
+	};
+};
+
+
+template <typename T>
+struct IsReference<T&>
+{
+	enum 
+	{
+		VALUE = 1
+	};
+};
+
+
+template <typename T>
+struct IsReference<const T&>
+{
+	enum 
+	{
+		VALUE = 1
+	};
+};
+
+
+template <typename T>
+struct IsConst
+	/// Use this struct to determine if a template type is a const type.
+{
+	enum
+	{
+		VALUE = 0
+	};
+};
+
+
+template <typename T>
+struct IsConst<const T&>
+{
+	enum 
+	{
+		VALUE = 1
+	};
+};
+
+
+template <typename T>
+struct IsConst<const T>
+{
+	enum 
+	{
+		VALUE = 1
+	};
+};
+
+
+template <typename T, int i>
+struct IsConst<const T[i]>
+	/// Specialization for const char arrays
+{
+	enum
+	{
+		VALUE = 1
+	};
+};
+
+
+template <typename T>
+struct TypeWrapper
+	/// Use the type wrapper if you want to decouple constness and references from template types.
+{
+	typedef T TYPE;
+	typedef const T CONSTTYPE;
+	typedef T& REFTYPE;
+	typedef const T& CONSTREFTYPE;
+};
+
+
+template <typename T>
+struct TypeWrapper<const T>
+{
+	typedef T TYPE;
+	typedef const T CONSTTYPE;
+	typedef T& REFTYPE;
+	typedef const T& CONSTREFTYPE;
+};
+
+
+template <typename T>
+struct TypeWrapper<const T&>
+{
+	typedef T TYPE;
+	typedef const T CONSTTYPE;
+	typedef T& REFTYPE;
+	typedef const T& CONSTREFTYPE;
+};
+
+
+template <typename T>
+struct TypeWrapper<T&>
+{
+	typedef T TYPE;
+	typedef const T CONSTTYPE;
+	typedef T& REFTYPE;
+	typedef const T& CONSTREFTYPE;
+};
+
+
+} // namespace Poco
+
+
+#endif // Foundation_MetaProgramming_INCLUDED