Modified ResourceHandler.deleteObject() to take a globally unique id (guid)
as input rather than a metacat-conformant docid. The guid is translated
into a metacat docid which is then used in the handleDelete() call. So now
Metacat supports use of arbitrary identifiers for delete operations, but
only through the MetacatRest REST service interface. Still need to handle
exceptions that should be generated when a guid is not found.