Updated domtest.xsd and simple attr.xml

I've updated my alternative XML Schema for DOM tests and started writing a few experimental test in preparation of attempting to convert my domunit/junit code to XML.

You can see a very simple Attr test (parentNodeNull) at
http://cvs.sourceforge.net/cgi-bin/viewcvs.cgi/xmlconf/domunit/DOM1/NIST/attr.xml?rev=1.2&content-type=text/vnd.viewcvs-markup

The updated schema is http://cvs.sourceforge.net/cgi-bin/viewcvs.cgi/xmlconf/domunit/domtest.xsd?rev=1.2&content-type=text/vnd.viewcvs-markup  

The files comply with the Oct 2000 Schema working draft since that currently has the best software support.

 I think it now has enough (or close to enough) constructs to handle the NIST DOM tests and has elements for all of the DOM 2 Core.

On the test metadata, my personal leaning would be to use the Dublin Core Proposed Recommendation "An XML Encoding of Simple Dublin Core Metadata" (http://dublincore.org/documents/2001/04/11/dcmes-xml/)  This would keep the metadata in a distinct file from the test in a format that was compatible with RDF and provides both a DTD and an attempt at an XML schema for the metadata.  One of the advantages of keeping the metadata distinct from the test definitions is that it is then easy to add additional description, notes, translations, without modifying the test definitions.