Please export Node,Element,AttributeNode etc. internal classes

[Torcsi]

During a (successful) implementation of SaxonJS with xmldom we needed the interface classes for the purpose of testing oNode instanceof Node.

https://www.w3.org/TR/2000/REC-DOM-Level-2-Core-20001113/core.html says in its TOC

1.2. Fundamental Interfaces

DOMException, ExceptionCode, DOMImplementation, DocumentFragment, Document, Node, NodeList, NamedNodeMap, CharacterData, Attr, Element, Text, Comment

Can you please add the exports in domparser and dom for these internal classes/interfaces? This is minor change but there may be some potential threats I am not aware of.

Thanks.

Btw. when exporting these (modifying manually the exports), SaxonJS gave definite life signs under node js.