evaluate and migrate ebi wsdbfetch client to use REST service

The EBI WsDbFetch service is available as a fully specified REST service (via WADL: http://www.ebi.ac.uk/Tools/webservices/services/dbfetch_rest ), as well as the original SOAP service that Jalview uses. Both appear to support the same functionality, however recent (Sep 2010) experience with the SOAP service suggests it's record fetching performance has degraded, and the REST service retrieved similar queries with greater speed when queried via the browser.

A new jalview.ws.ebi.EBIFetchClient implementation should be created that uses the REST service, but otherwise implements the same public methods (i.e. retrieves to a file, and then passes the file path back to Jalview). Tests can be performed to investigate performance, and should the REST service prove superiour, the implementation should be switched.