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/IntValidator.cpp

@@ -0,0 +1,54 @@
+//
+// IntValidator.cpp
+//
+// Library: Util
+// Package: Options
+// Module:  IntValidator
+//
+// Copyright (c) 2006, Applied Informatics Software Engineering GmbH.
+// and Contributors.
+//
+// SPDX-License-Identifier:	BSL-1.0
+//
+
+
+#include "Poco/Util/IntValidator.h"
+#include "Poco/Util/Option.h"
+#include "Poco/Util/OptionException.h"
+#include "Poco/NumberParser.h"
+#include "Poco/Format.h"
+
+
+using Poco::NumberParser;
+using Poco::format;
+
+
+namespace Poco {
+namespace Util {
+
+
+IntValidator::IntValidator(int min, int max):
+	_min(min),
+	_max(max)
+{
+}
+
+
+IntValidator::~IntValidator()
+{
+}
+
+
+void IntValidator::validate(const Option& option, const std::string& value)
+{
+	int n;
+	if (NumberParser::tryParse(value, n))
+	{
+		if (n < _min || n > _max)
+			throw InvalidArgumentException(format("argument for %s must be in range %d to %d", option.fullName(), _min, _max));
+	}
+	else throw InvalidArgumentException(format("argument for %s must be an integer", option.fullName()));
+}
+
+
+} } // namespace Poco::Util