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/XML/include/Poco/SAX/SAXException.h

@@ -0,0 +1,176 @@
+//
+// SAXException.h
+//
+// Library: XML
+// Package: SAX
+// Module:  SAX
+//
+// SAX exception classes.
+//
+// Copyright (c) 2004-2006, Applied Informatics Software Engineering GmbH.
+// and Contributors.
+//
+// SPDX-License-Identifier:	BSL-1.0
+//
+
+
+#ifndef SAX_SAXException_INCLUDED
+#define SAX_SAXException_INCLUDED
+
+
+#include "Poco/XML/XML.h"
+#include "Poco/XML/XMLException.h"
+#include "Poco/XML/XMLString.h"
+
+
+namespace Poco {
+namespace XML {
+
+
+POCO_DECLARE_EXCEPTION(XML_API, SAXException, XMLException)
+	/// The base class for all SAX-related exceptions like SAXParseException,
+	/// SAXNotRecognizedException or SAXNotSupportedException.
+	/// 
+	/// This class can contain basic error or warning information from either the XML parser 
+	/// or the application: a parser writer or application writer can subclass it to provide 
+	/// additional functionality. SAX handlers may throw this exception or any exception subclassed 
+	/// from it.
+	/// 
+	/// If the application needs to pass through other types of exceptions, it must wrap those exceptions 
+	/// in a SAXException or an exception derived from a SAXException.
+	/// 
+	/// If the parser or application needs to include information about a specific location in an XML 
+	/// document, it should use the SAXParseException subclass.
+
+
+POCO_DECLARE_EXCEPTION(XML_API, SAXNotRecognizedException, SAXException)
+	/// Exception class for an unrecognized identifier.
+	/// 
+	/// An XMLReader will throw this exception when it finds an unrecognized feature or property 
+	/// identifier; SAX applications and extensions may use this class for other, similar purposes.
+
+
+POCO_DECLARE_EXCEPTION(XML_API, SAXNotSupportedException, SAXException)
+	/// Exception class for an unsupported operation.
+	/// 
+	/// An XMLReader will throw this exception when it recognizes a feature or property identifier, 
+	/// but cannot perform the requested operation (setting a state or value). Other SAX2 applications 
+	/// and extensions may use this class for similar purposes.
+
+
+class Locator;
+
+
+class XML_API SAXParseException: public SAXException
+	/// Encapsulate an XML parse error or warning.
+	///
+	/// This exception may include information for locating the error in the original XML document, 
+	/// as if it came from a Locator object. Note that although the application will receive a 
+	/// SAXParseException as the argument to the handlers in the ErrorHandler interface, the application 
+	/// is not actually required to throw the exception; instead, it can simply read the information in it 
+	/// and take a different action.
+	/// 
+	/// Since this exception is a subclass of SAXException, it inherits the ability to wrap another exception.
+{
+public:	
+	SAXParseException(const std::string& msg, const Locator& loc);
+		/// Create a new SAXParseException from a message and a Locator.
+
+	SAXParseException(const std::string& msg, const Locator& loc, const Poco::Exception& exc);
+		/// Wrap an existing exception in a SAXParseException.
+
+	SAXParseException(const std::string& msg, const XMLString& publicId, const XMLString& systemId, int lineNumber, int columnNumber);
+		/// Create a new SAXParseException with an embedded exception.
+		/// 
+		/// This constructor is most useful for parser writers.
+		/// All parameters except the message are as if they were provided by a Locator. 
+		/// For example, if the system identifier is a URL (including relative filename), 
+		/// the caller must resolve it fully before creating the exception.
+
+	SAXParseException(const std::string& msg, const XMLString& publicId, const XMLString& systemId, int lineNumber, int columnNumber, const Poco::Exception& exc);
+		/// Create a new SAXParseException.
+		/// 
+		/// This constructor is most useful for parser writers.
+		/// All parameters except the message are as if they were provided by a Locator. 
+		/// For example, if the system identifier is a URL (including relative filename), 
+		/// the caller must resolve it fully before creating the exception.
+
+	SAXParseException(const SAXParseException& exc);
+		/// Creates a new SAXParseException from another one.
+
+	~SAXParseException() noexcept;
+		/// Destroy the exception.
+
+	SAXParseException& operator = (const SAXParseException& exc);
+		/// Assignment operator.
+		
+	const char* name() const noexcept;
+		/// Returns a static string describing the exception.
+
+	const char* className() const noexcept;
+		/// Returns the name of the exception class.
+
+	Poco::Exception* clone() const;
+		/// Creates an exact copy of the exception.
+		
+	void rethrow() const;
+		/// (Re)Throws the exception.
+
+	const XMLString& getPublicId() const;
+		/// Get the public identifier of the entity where the exception occurred.
+		
+	const XMLString& getSystemId() const;
+		/// Get the system identifier of the entity where the exception occurred.
+		
+	int getLineNumber() const;
+		/// The line number of the end of the text where the exception occurred.
+		/// The first line is line 1.
+		
+	int getColumnNumber() const;
+		/// The column number of the end of the text where the exception occurred.
+		/// The first column in a line is position 1.
+
+protected:
+	static std::string buildMessage(const std::string& msg, const XMLString& publicId, const XMLString& systemId, int lineNumber, int columnNumber);
+	
+private:
+	SAXParseException();
+
+	XMLString _publicId;
+	XMLString _systemId;
+	int       _lineNumber;
+	int       _columnNumber;
+};
+
+
+//
+// inlines
+//
+inline const XMLString& SAXParseException::getPublicId() const
+{
+	return _publicId;
+}
+
+
+inline const XMLString& SAXParseException::getSystemId() const
+{
+	return _systemId;
+}
+
+
+inline int SAXParseException::getLineNumber() const
+{
+	return _lineNumber;
+}
+
+
+inline int SAXParseException::getColumnNumber() const
+{
+	return _columnNumber;
+}
+
+
+} } // namespace Poco::XML
+
+
+#endif // SAX_SAXException_INCLUDED