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/Util/src/MapConfiguration.cpp

@@ -0,0 +1,122 @@
+//
+// MapConfiguration.cpp
+//
+// Library: Util
+// Package: Configuration
+// Module:  MapConfiguration
+//
+// Copyright (c) 2004-2006, Applied Informatics Software Engineering GmbH.
+// and Contributors.
+//
+// SPDX-License-Identifier:	BSL-1.0
+//
+
+
+#include "Poco/Util/MapConfiguration.h"
+#include <set>
+
+
+namespace Poco {
+namespace Util {
+
+
+MapConfiguration::MapConfiguration()
+{
+}
+
+
+MapConfiguration::~MapConfiguration()
+{
+}
+
+
+void MapConfiguration::copyTo(AbstractConfiguration& config)
+{
+	for (const auto& p: _map)
+	{
+		config.setString(p.first, p.second);
+	}
+}
+
+
+void MapConfiguration::clear()
+{
+	_map.clear();
+}
+
+
+bool MapConfiguration::getRaw(const std::string& key, std::string& value) const
+{
+	StringMap::const_iterator it = _map.find(key);
+	if (it != _map.end())
+	{
+		value = it->second;
+		return true;
+	}
+	else return false;
+}
+
+
+void MapConfiguration::setRaw(const std::string& key, const std::string& value)
+{
+	_map[key] = value;
+}
+
+
+void MapConfiguration::enumerate(const std::string& key, Keys& range) const
+{
+	std::set<std::string> keys;
+	std::string prefix = key;
+	if (!prefix.empty()) prefix += '.';
+	std::string::size_type psize = prefix.size();
+	for (const auto& p: _map)
+	{
+		if (p.first.compare(0, psize, prefix) == 0)
+		{
+			std::string subKey;
+			std::string::size_type end = p.first.find('.', psize);
+			if (end == std::string::npos)
+				subKey = p.first.substr(psize);
+			else
+				subKey = p.first.substr(psize, end - psize);
+			if (keys.find(subKey) == keys.end())
+			{
+				range.push_back(subKey);
+				keys.insert(subKey);
+			}
+		}
+	}
+}
+
+
+void MapConfiguration::removeRaw(const std::string& key)
+{
+	std::string prefix = key;
+	if (!prefix.empty()) prefix += '.';
+	std::string::size_type psize = prefix.size();
+	StringMap::iterator it = _map.begin();
+	StringMap::iterator itCur;
+	while (it != _map.end())
+	{
+		itCur = it++;
+		if ((itCur->first == key) || (itCur->first.compare(0, psize, prefix) == 0))
+		{
+			_map.erase(itCur);
+		}
+	}
+}
+
+
+MapConfiguration::iterator MapConfiguration::begin() const
+{
+	return _map.begin();
+}
+
+
+MapConfiguration::iterator MapConfiguration::end() const
+{
+	return _map.end();
+}
+
+
+} } // namespace Poco::Util