Parses xml document specified by url and resolves it to one node.
First tries to retrieve xml document from cache.
If it is not cached then reads it, parses it and caches (if needed).
Then if there is no any xpath expression in url returns Document itself as a xml node.
If there is some Xpath then evaluates this XPath to one xml node and returns it.
The url's format: #
Example: http://myserver.com/mydata.xml#/doc/item/firstNode
Parameters: url - url to xml document xml node exception: IOException - exception: SAXException - |