Import XML XML Schema [sic]

This allows use of xml:lang.

Downloaded from:
<http://www.w3.org/2005/08/xml.xsd>

Signed-off-by: Alex Nelson <a.nelson@prometheuscomputing.com>
Add local copy of Dublin Core metadata

The 'xmllint' utility requires all referenced schemas be available.
Downloading the schema once saves on future network transmissions.

Downloaded from:
<http://www.dublincore.org/schemas/xmls/qdc/2008/02/11/dc.xsd>

Signed-off-by: Alex Nelson <a.nelson@prometheuscomputing.com>
Allow offline validation with local XSD cache

Signed-off-by: Alex Nelson <a.nelson@prometheuscomputing.com>
Replace fileobject.xsd with rewritten schema, dfxml.xsd

Version 1.1.0rfc0: request for comments.

Signed-off-by: Alex Nelson <a.nelson@prometheuscomputing.com>
Signed-off-by: John Tebbutt <john.tebbutt@nist.gov>
Signed-off-by: Mary Laamanen <mary.laamanen@nist.gov>