CURIE_REGEX needs to be broadened

[linclark]

The CURIE_REGEX doesn't allow for some of the characters that are allowed by the XML 1.0 Namespace specification.

These include underscores, some Unicode chars, etc.

See more here: http://www.w3.org/TR/xml-names11/#NT-NCName

[linclark]

This can now use the regular expression defined in rdfx.inc