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/Locator.h

@@ -0,0 +1,103 @@
+//
+// Locator.h
+//
+// Library: XML
+// Package: SAX
+// Module:  SAX
+//
+// SAX Locator Interface.
+//
+// Copyright (c) 2004-2006, Applied Informatics Software Engineering GmbH.
+// and Contributors.
+//
+// SPDX-License-Identifier:	BSL-1.0
+//
+
+
+#ifndef SAX_Locator_INCLUDED
+#define SAX_Locator_INCLUDED
+
+
+#include "Poco/XML/XML.h"
+#include "Poco/XML/XMLString.h"
+
+
+namespace Poco {
+namespace XML {
+
+
+class XML_API Locator
+	/// Interface for associating a SAX event with a document location.
+	/// 
+	/// If a SAX parser provides location information to the SAX application, it does so by 
+	/// implementing this interface and then passing an instance to the application using the 
+	/// content handler's setDocumentLocator method. The application can use the object to obtain 
+	/// the location of any other SAX event in the XML source document.
+	/// 
+	/// Note that the results returned by the object will be valid only during the scope of each 
+	/// callback method: the application will receive unpredictable results if it attempts to use 
+	/// the locator at any other time, or after parsing completes.
+	/// 
+	/// SAX parsers are not required to supply a locator, but they are very strongly encouraged to 
+	/// do so. If the parser supplies a locator, it must do so before reporting any other document 
+	/// events. If no locator has been set by the time the application receives the startDocument event, 
+	/// the application should assume that a locator is not available.
+{
+public:
+	virtual XMLString getPublicId() const = 0;
+		/// Return the public identifier for the current document event.
+		/// 
+		/// The return value is the public identifier of the document entity or of the external 
+		/// parsed entity in which the markup triggering the event appears.
+
+	virtual XMLString getSystemId() const = 0;
+		/// Return the system identifier for the current document event.
+		/// 
+		/// The return value is the system identifier of the document entity or of the external 
+		/// parsed entity in which the markup triggering the event appears.
+		/// 
+		/// If the system identifier is a URL, the parser must resolve it fully before passing 
+		/// it to the application. For example, a file name must always be provided as a 
+		/// file:... URL, and other kinds of relative URI are also resolved against their bases.
+
+	virtual int getLineNumber() const = 0;
+		/// Return the line number where the current document event ends.
+		/// Lines are delimited by line ends, which are defined in the XML specification.
+		/// 
+		/// Warning: The return value from the method is intended only as an approximation for 
+		/// the sake of diagnostics; it is not intended to provide sufficient information to 
+		/// edit the character content of the original XML document. In some cases, these "line" 
+		/// numbers match what would be displayed as columns, and in others they may not match the 
+		/// source text due to internal entity expansion.
+		/// 
+		/// The return value is an approximation of the line number in the document entity or external 
+		/// parsed entity where the markup triggering the event appears.
+		/// 
+		/// If possible, the SAX driver should provide the line position of the first character after 
+		/// the text associated with the document event. The first line is line 1.
+
+	virtual int getColumnNumber() const = 0;
+		/// Return the column number where the current document event ends. 
+		/// This is one-based number of characters since the last line end.
+		/// 
+		/// Warning: The return value from the method is intended only as an approximation 
+		/// for the sake of diagnostics; it is not intended to provide sufficient information 
+		/// to edit the character content of the original XML document. For example, when lines 
+		/// contain combining character sequences, wide characters, surrogate pairs, or bi-directional 
+		/// text, the value may not correspond to the column in a text editor's display.
+		/// 
+		/// The return value is an approximation of the column number in the document entity or external 
+		/// parsed entity where the markup triggering the event appears.
+		/// 
+		/// If possible, the SAX driver should provide the line position of the first character after 
+		/// the text associated with the document event. The first column in each line is column 1.
+
+protected:
+	virtual ~Locator();
+};
+
+
+} } // namespace Poco::XML
+
+
+#endif // SAX_Locator_INCLUDED