DataONE API Refinements and validation script

Addresses issues in Trello 9
Fixes ORE identifier URIs in resource map documents
Updates the Dryad 3.1 xml schema so that data packages do not require a <dcterms:references> (article DOI) element
Fixes the DOIDbSync utility to catch IdentifierNotFound exceptions and update the DOI.db database with new identifiers - This utility appears to have not been functional for a long time
Adds curator reports to identify insufficient metadata, but these are superseded by the python script
Adds a python script that uses xmllint to validate items against the dryad schema, to identify issues before DataONE imports the data