Character stream that handles (or at least attemtps to) all the necessary Voodo to figure out
the charset encoding of the XML document within the stream.
IMPORTANT: This class is not related in any way to the org.xml.sax.XMLReader.
The XmlReaderException is thrown by the XmlReader constructors if the charset encoding
can not be determined according to the XML 1.0 specification and RFC 3023.
The exception returns the unconsumed InputStream to allow the application to do an
alternate processing with the stream.