CEHCIG-789 plone update service

This adds a Plone data deposit service that updates EIDC's data inventory in Plone.  It is used in the UploadController when an upload is being processed.  All responses from Plone that don't have a 200 status code are thrown as a RuntimeException to the controller.  In the case of a 400 status code (Bad Request) the RuntimeException will contain info. about the nature of the problem (eg querystring was missing a 'title' parameter).

After a successful upload, the EIDC Data Inventory (eg http://eidctest.ceh.ac.uk/administration-folder/eidc-data-inventory) can be searched to see the new Data Deposit that has been created or updated.

See merge request !68