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/Dynamic/Pair.h

@@ -0,0 +1,412 @@
+//
+// Pair.h
+//
+// Library: Foundation
+// Package: Dynamic
+// Module:  Pair
+//
+// Definition of the Pair class.
+//
+// Copyright (c) 2007, Applied Informatics Software Engineering GmbH.
+// and Contributors.
+//
+// SPDX-License-Identifier:	BSL-1.0
+//
+
+
+#ifndef Foundation_Pair_INCLUDED
+#define Foundation_Pair_INCLUDED
+
+
+#include "Poco/Foundation.h"
+#include "Poco/Dynamic/Var.h"
+#include "Poco/Dynamic/VarHolder.h"
+#include <utility>
+
+
+namespace Poco {
+namespace Dynamic {
+
+
+template <typename K>
+class Pair
+	/// Pair allows to define a pair of values.
+{
+public:
+	using Data = typename std::pair<K, Var>;
+
+	Pair(): _data()
+		/// Creates an empty Pair
+	{
+	}
+
+	Pair(const Pair& other): _data(other._data)
+		/// Creates the Pair from another pair.
+	{
+	}
+
+	Pair(const Data& val): _data(val)
+		/// Creates the Pair from the given value.
+	{
+	}
+
+	template <typename T>
+	Pair(const std::pair<K, T>& val): _data(std::make_pair(val.first, val.second))
+		/// Creates Pair form standard pair.
+	{
+	}
+
+	template <typename T>
+	Pair(const K& first, const T& second): _data(std::make_pair(first, second))
+		/// Creates pair from two values.
+	{
+	}
+
+	virtual ~Pair()
+		/// Destroys the Pair.
+	{
+	}
+
+	Pair& swap(Pair& other)
+		/// Swaps the content of the two Pairs.
+	{
+		std::swap(_data, other._data);
+		return *this;
+	}
+
+	Pair& operator = (const Pair& other)
+		/// Copy constructs Pair from another pair.
+	{
+		Pair(other).swap(*this);
+		return *this;
+	}
+
+	inline const K& first() const
+		/// Returns the first member of the pair.
+	{
+		return _data.first;
+	}
+
+	inline const Var& second() const
+		/// Returns the second member of the pair.
+	{
+		return _data.second;
+	}
+
+	std::string toString()
+	{
+		std::string str;
+		Var(*this).template convert<std::string>(str);
+		return str;
+	}
+
+private:
+	Data _data;
+};
+
+
+template <>
+class VarHolderImpl<Pair<std::string>>: public VarHolder
+{
+public:
+	VarHolderImpl(const Pair<std::string>& val): _val(val)
+	{
+	}
+
+	~VarHolderImpl()
+	{
+	}
+	
+	const std::type_info& type() const
+	{
+		return typeid(Pair<std::string>);
+	}
+
+	void convert(Int8& val) const
+	{
+		throw BadCastException("Cannot cast Pair type to Int8");
+	}
+
+	void convert(Int16& val) const
+	{
+		throw BadCastException("Cannot cast Pair type to Int16");
+	}
+	
+	void convert(Int32& val) const
+	{
+		throw BadCastException("Cannot cast Pair type to Int32");
+	}
+
+	void convert(Int64& val) const
+	{
+		throw BadCastException("Cannot cast Pair type to Int64");
+	}
+
+	void convert(UInt8& val) const
+	{
+		throw BadCastException("Cannot cast Pair type to UInt8");
+	}
+
+	void convert(UInt16& val) const
+	{
+		throw BadCastException("Cannot cast Pair type to UInt16");
+	}
+	
+	void convert(UInt32& val) const
+	{
+		throw BadCastException("Cannot cast Pair type to UInt32");
+	}
+
+	void convert(UInt64& val) const
+	{
+		throw BadCastException("Cannot cast Pair type to UInt64");
+	}
+
+	void convert(bool& val) const
+	{
+		throw BadCastException("Cannot cast Pair type to bool");
+	}
+
+	void convert(float& val) const
+	{
+		throw BadCastException("Cannot cast Pair type to float");
+	}
+
+	void convert(double& val) const
+	{
+		throw BadCastException("Cannot cast Pair type to double");
+	}
+
+	void convert(char& val) const
+	{
+		throw BadCastException("Cannot cast Pair type to char");
+	}
+
+	void convert(std::string& val) const
+	{
+		// Serialize in JSON format: equals an object
+		// JSON format definition: { string ':' value } string:value pair n-times, sep. by ','
+		val.append("{ ");
+		Var key(_val.first());
+		Impl::appendJSONKey(val, key);
+		val.append(" : ");
+		Impl::appendJSONValue(val, _val.second());
+		val.append(" }");	
+	}
+
+	void convert(Poco::DateTime&) const
+	{
+		throw BadCastException("Pair -> Poco::DateTime");
+	}
+
+	void convert(Poco::LocalDateTime&) const
+	{
+		throw BadCastException("Pair -> Poco::LocalDateTime");
+	}
+
+	void convert(Poco::Timestamp&) const
+	{
+		throw BadCastException("Pair -> Poco::Timestamp");
+	}
+
+	VarHolder* clone(Placeholder<VarHolder>* pVarHolder = 0) const
+	{
+		return cloneHolder(pVarHolder, _val);
+	}
+	
+	const Pair<std::string>& value() const
+	{
+		return _val;
+	}
+
+	bool isArray() const
+	{
+		return false;
+	}
+
+	bool isStruct() const
+	{
+		return false;
+	}
+
+	bool isInteger() const
+	{
+		return false;
+	}
+
+	bool isSigned() const
+	{
+		return false;
+	}
+
+	bool isNumeric() const
+	{
+		return false;
+	}
+
+	bool isString() const
+	{
+		return false;
+	}
+
+private:
+	Pair<std::string> _val;
+};
+
+
+template <>
+class VarHolderImpl<Pair<int>>: public VarHolder
+{
+public:
+	VarHolderImpl(const Pair<int>& val): _val(val)
+	{
+	}
+
+	~VarHolderImpl()
+	{
+	}
+	
+	const std::type_info& type() const
+	{
+		return typeid(Pair<int>);
+	}
+
+	void convert(Int8& val) const
+	{
+		throw BadCastException("Cannot cast Pair type to Int8");
+	}
+
+	void convert(Int16& val) const
+	{
+		throw BadCastException("Cannot cast Pair type to Int16");
+	}
+	
+	void convert(Int32& val) const
+	{
+		throw BadCastException("Cannot cast Pair type to Int32");
+	}
+
+	void convert(Int64& val) const
+	{
+		throw BadCastException("Cannot cast Pair type to Int64");
+	}
+
+	void convert(UInt8& val) const
+	{
+		throw BadCastException("Cannot cast Pair type to UInt8");
+	}
+
+	void convert(UInt16& val) const
+	{
+		throw BadCastException("Cannot cast Pair type to UInt16");
+	}
+	
+	void convert(UInt32& val) const
+	{
+		throw BadCastException("Cannot cast Pair type to UInt32");
+	}
+
+	void convert(UInt64& val) const
+	{
+		throw BadCastException("Cannot cast Pair type to UInt64");
+	}
+
+	void convert(bool& val) const
+	{
+		throw BadCastException("Cannot cast Pair type to bool");
+	}
+
+	void convert(float& val) const
+	{
+		throw BadCastException("Cannot cast Pair type to float");
+	}
+
+	void convert(double& val) const
+	{
+		throw BadCastException("Cannot cast Pair type to double");
+	}
+
+	void convert(char& val) const
+	{
+		throw BadCastException("Cannot cast Pair type to char");
+	}
+
+	void convert(std::string& val) const
+	{
+		// Serialize in JSON format: equals an object
+		// JSON format definition: { string ':' value } string:value pair n-times, sep. by ','
+		val.append("{ ");
+		Var key(_val.first());
+		Impl::appendJSONKey(val, key);
+		val.append(" : ");
+		Impl::appendJSONValue(val, _val.second());
+		val.append(" }");	
+	}
+
+	void convert(Poco::DateTime&) const
+	{
+		throw BadCastException("Pair -> Poco::DateTime");
+	}
+
+	void convert(Poco::LocalDateTime&) const
+	{
+		throw BadCastException("Pair -> Poco::LocalDateTime");
+	}
+
+	void convert(Poco::Timestamp&) const
+	{
+		throw BadCastException("Pair -> Poco::Timestamp");
+	}
+
+	VarHolder* clone(Placeholder<VarHolder>* pVarHolder = 0) const
+	{
+		return cloneHolder(pVarHolder, _val);
+	}
+	
+	const Pair<int>& value() const
+	{
+		return _val;
+	}
+
+	bool isArray() const
+	{
+		return false;
+	}
+
+	bool isStruct() const
+	{
+		return false;
+	}
+
+	bool isInteger() const
+	{
+		return false;
+	}
+
+	bool isSigned() const
+	{
+		return false;
+	}
+
+	bool isNumeric() const
+	{
+		return false;
+	}
+
+	bool isString() const
+	{
+		return false;
+	}
+
+private:
+	Pair<int> _val;
+};
+
+
+} // namespace Dynamic
+
+
+} // namespace Poco
+
+
+#endif // Foundation_Pair_INCLUDED

vendor/POCO/Foundation/include/Poco/Dynamic/VarIterator.h

@@ -0,0 +1,155 @@
+//
+// VarIterator.h
+//
+// Library: Foundation
+// Package: Dynamic
+// Module:  VarIterator
+//
+// Definition of the VarIterator class.
+//
+// Copyright (c) 2006, Applied Informatics Software Engineering GmbH.
+// and Contributors.
+//
+// SPDX-License-Identifier:	BSL-1.0
+//
+
+
+#ifndef Foundation_VarIterator_INCLUDED
+#define Foundation_VarIterator_INCLUDED
+
+
+#include "Poco/Exception.h"
+#include <iterator>
+#include <algorithm>
+
+
+namespace Poco {
+namespace Dynamic {
+
+
+class Var;
+
+
+class Foundation_API VarIterator
+	/// VarIterator class.
+{
+public:
+	typedef std::bidirectional_iterator_tag iterator_category;
+	typedef Var                             value_type;
+	typedef std::ptrdiff_t                  difference_type;
+	typedef Var*                            pointer;
+	typedef Var&                            reference;
+
+	static const std::size_t POSITION_END;
+		/// End position indicator.
+
+	VarIterator(Var* pVar, bool positionEnd);
+		/// Creates the VarIterator and positions it at the end of
+		/// the recordset if positionEnd is true. Otherwise, it is
+		/// positioned at the beginning.
+
+	VarIterator(const VarIterator& other);
+		/// Creates a copy of other VarIterator.
+
+	VarIterator(VarIterator&& other) noexcept;
+		/// Moves another VarIterator.
+
+	~VarIterator();
+		/// Destroys the VarIterator.
+
+	VarIterator& operator = (const VarIterator& other);
+		/// Assigns the other VarIterator.
+
+	VarIterator& operator = (VarIterator&& other) noexcept;
+		/// Assigns the other VarIterator.
+
+	bool operator == (const VarIterator& other) const;
+		/// Equality operator.
+
+	bool operator != (const VarIterator& other) const;
+		/// Inequality operator.
+
+	Var& operator * () const;
+		/// Returns value at the current position.
+
+	Var* operator -> () const;
+		/// Returns pointer to the value at current position.
+
+	const VarIterator& operator ++ () const;
+		/// Advances by one position and returns current position.
+
+	VarIterator operator ++ (int) const;
+		/// Advances by one position and returns copy of the iterator with 
+		/// previous current position.
+
+	const VarIterator& operator -- () const;
+		/// Goes back by one position and returns copy of the iterator with 
+		/// previous current position.
+
+	VarIterator operator -- (int) const;
+		/// Goes back by one position and returns previous current position.
+
+	VarIterator operator + (std::size_t diff) const;
+		/// Returns a copy the VarIterator advanced by diff positions.
+
+	VarIterator operator - (std::size_t diff) const;
+		/// Returns a copy the VarIterator backed by diff positions.
+		/// Throws RangeException if diff is larger than current position.
+
+	void swap(VarIterator& other);
+		/// Swaps the VarIterator with another one.
+
+private:
+	VarIterator();
+
+	void increment() const;
+		/// Increments the iterator position by one. 
+		/// Throws RangeException if position is out of range.
+
+	void decrement() const;
+		/// Decrements the iterator position by one. 
+		/// Throws RangeException if position is out of range.
+
+	void setPosition(std::size_t pos) const;
+		/// Sets the iterator position. 
+		/// Throws RangeException if position is out of range.
+
+	Var*                _pVar;
+	mutable std::size_t _position;
+
+	friend class Var;
+};
+
+
+///
+/// inlines
+///
+
+
+inline bool VarIterator::operator == (const VarIterator& other) const
+{
+	return _pVar == other._pVar && _position == other._position;
+}
+
+
+inline bool VarIterator::operator != (const VarIterator& other) const
+{
+	return _pVar != other._pVar || _position != other._position;
+}
+
+
+} } // namespace Poco::Dynamic
+
+
+namespace std
+{
+	template<>
+	inline void swap<Poco::Dynamic::VarIterator>(Poco::Dynamic::VarIterator& s1, Poco::Dynamic::VarIterator& s2) noexcept
+		/// Full template specialization of std:::swap for VarIterator
+	{
+		s1.swap(s2);
+	}
+}
+
+
+#endif // Foundation_VarIterator_INCLUDED