CTS: Implemented basic handling of identityref type.
CTS: Implemented basic handling of identityref type.

This only covers the RELAX NG part (QName type constraint).
The value will be checked in Schematron - we need a new annotation
giving all possible values in the form (nsURI, identity_name).
krvinay123/test,kspviswa/pyang,vkosuri/pyang,jgatkinsn/pyang,mbj4668/pyang,davidegurgone/pyang,acidjunk/pyang,kspviswa/pyang,brenoah/pyang,acidjunk/pyang,vkosuri/pyang,krvinay123/test,jgatkinsn/pyang,brenoah/pyang,davidegurgone/pyang,mbj4668/pyang