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/DOM/DOMObject.h

@@ -0,0 +1,103 @@
+//
+// DOMObject.h
+//
+// Library: XML
+// Package: DOM
+// Module:  DOM
+//
+// Definition of the DOMObject class.
+//
+// Copyright (c) 2004-2006, Applied Informatics Software Engineering GmbH.
+// and Contributors.
+//
+// SPDX-License-Identifier:	BSL-1.0
+//
+
+
+#ifndef DOM_DOMObject_INCLUDED
+#define DOM_DOMObject_INCLUDED
+
+
+#include "Poco/XML/XML.h"
+
+
+namespace Poco {
+namespace XML {
+
+
+class XML_API DOMObject
+	/// The base class for all objects in the Document Object Model.
+	///
+	/// DOMObject defines the rules for memory management
+	/// in this implementation of the DOM. Violation of these
+	/// rules, which are outlined in the following, results
+	/// in memory leaks or dangling pointers.
+	///
+	/// Every object created by new or by a factory
+	/// method (for example, Document::create*) must be released
+	/// with a call to release() or autoRelease() when it
+	/// is no longer needed.
+	///
+	/// Every object created by cloning or importing another
+	/// object must be released.
+	/// For every call to duplicate() there must be a matching
+	/// call to release().
+	/// An object obtained via any other way must not be
+	/// released, except ownership of it has been explicitly
+	/// taken with a call to duplicate().
+	///
+	/// While DOMObjects are safe for use in multithreaded programs,
+	/// a DOMObject or one of its subclasses must not be accessed
+	/// from multiple threads simultaneously.
+{
+public:
+	DOMObject();
+		/// Creates the DOMObject.
+		/// The object's reference count is initialized to one.
+
+	void duplicate() const;
+		/// Increases the object's reference count.
+
+	void release() const;
+		/// Decreases the object's reference count.
+		/// If the reference count reaches zero,
+		/// the object is deleted.
+		
+	virtual void autoRelease() = 0;
+		/// Adds the object to an appropriate
+		/// AutoReleasePool, which is usually the
+		/// AutoReleasePool managed by the Document
+		/// to which this object belongs.
+
+protected:
+	virtual ~DOMObject();
+		/// Destroys the DOMObject.
+
+private:
+	DOMObject(const DOMObject&);
+	DOMObject& operator = (const DOMObject&);
+	
+	mutable int _rc;
+};
+
+
+//
+// inlines
+//
+inline void DOMObject::duplicate() const
+{
+	++_rc;
+}
+
+
+inline void DOMObject::release() const
+{
+	if (--_rc == 0)
+		delete this;
+}
+
+
+} } // namespace Poco::XML
+
+
+#endif // DOM_DOMObject_INCLUDED