Characters legal in XML 1.1 are not accepted

I ported some code from Tango's SaxParser to dxml, and it choked on a file with illegal characters like ASCII character 1 (SOH) in it. XML 1.1 allows these, but only in the form of character references. Tango seems to just pass them through, even in plain form.

I also noticed that encodeAttr and encodeCharRef does not seem to care.