Resolve correct Ensembl REST API endpoint for Uniprot crossreferences to Ensembl

Uniprot subdivides Ensembl cross references by division (protists, bacteria, etc), and Jalview needs to know which REST endpoint to query for these when resolving cross-references.

See http://www.uniprot.org/database/?query=*&fil=category%3A%22Genome+annotation+databases%22 for details of the cross references as maintained by Uniprot. Could possibly resolve Ensembl endpoint by parsing the URL template field associated with each Uniprot cross-reference database records (e.g. http://www.uniprot.org/database/DB-0147 )