attribute::* selects all the attributes of the context node
<?xgrep-match [xgrep-test1.xml]--------------------------------?>
{}name="xgrep tests"
<?xgrep-match [xgrep-test1.xml]--------------------------------?>
{}param="param2"
<?xgrep-match [xgrep-test1.xml]--------------------------------?>
{http://www.w3.org/2001/XMLSchema-instance}schemaLocation="http://www.theborg.org xgrep-test1.xsd"