[xml] hexBinary update

[Charles Bozeman <cbozeman hiwaay net>]

This patch implements hexBinary values as strings. I've also included
test code for validating hexBinary types.

C. Bozeman

Attachment: xmlschemastypes.c-pat
Description: Text Data

Attachment: hexbinary_0.xml
Description: Text Data

Attachment: hexbinary_0.xsd
Description: Text document

Attachment: hexbinary_1.xml
Description: Text Data