XMLSecurityStreamReader ignores information in XML document declaration

XMLSecurityStreamReader ignores information such as version, character encoding scheme and standalone-ness in the XML document declaration.
The implementation always returns null/false, indicating the defaults version "1.0", character encoding scheme "UTF-8", even if the XML document specifies something else.

The following example will have the wrong version, encoding and standalone-ness:

<?xml version='1.1' encoding='ISO-8859-1' standalone='yes'?>
</Document>