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/EntityReference.h

@@ -0,0 +1,73 @@
+//
+// EntityReference.h
+//
+// Library: XML
+// Package: DOM
+// Module:  DOM
+//
+// Definition of the DOM EntityReference class.
+//
+// Copyright (c) 2004-2006, Applied Informatics Software Engineering GmbH.
+// and Contributors.
+//
+// SPDX-License-Identifier:	BSL-1.0
+//
+
+
+#ifndef DOM_EntityReference_INCLUDED
+#define DOM_EntityReference_INCLUDED
+
+
+#include "Poco/XML/XML.h"
+#include "Poco/DOM/AbstractNode.h"
+#include "Poco/XML/XMLString.h"
+
+
+namespace Poco {
+namespace XML {
+
+
+class XML_API EntityReference: public AbstractNode
+	/// EntityReference objects may be inserted into the structure model when an
+	/// entity reference is in the source document, or when the user wishes to insert
+	/// an entity reference. Note that character references and references to predefined
+	/// entities are considered to be expanded by the HTML or XML processor so that
+	/// characters are represented by their Unicode equivalent rather than by an
+	/// entity reference. Moreover, the XML processor may completely expand references
+	/// to entities while building the structure model, instead of providing EntityReference
+	/// objects. If it does provide such objects, then for a given EntityReference
+	/// node, it may be that there is no Entity node representing the referenced
+	/// entity. If such an Entity exists, then the child list of the EntityReference
+	/// node is the same as that of the Entity node.
+	/// 
+	/// As for Entity nodes, EntityReference nodes and all their descendants are
+	/// readonly.
+	/// 
+	/// The resolution of the children of the EntityReference (the replacement value
+	/// of the referenced Entity) may be lazily evaluated; actions by the user (such
+	/// as calling the childNodes method on the EntityReference node) are assumed
+	/// to trigger the evaluation.
+{
+public:
+	// Node
+	const XMLString& nodeName() const;
+	unsigned short nodeType() const;
+
+protected:
+	EntityReference(Document* pOwnerDocument, const XMLString& name);
+	EntityReference(Document* pOwnerDocument, const EntityReference& ref);
+	~EntityReference();
+
+	Node* copyNode(bool deep, Document* pOwnerDocument) const;
+
+private:
+	XMLString _name;
+	
+	friend class Document;
+};
+
+
+} } // namespace Poco::XML
+
+
+#endif // DOM_EntityReference_INCLUDED