Add support for CRUD operations using batch schemantics in OData

RESTLET: Add support for batch operations on the client.
Shouldn't the header come before the entity representation? This is the example from the OData V3 specs.

I know that we are not setting the content-ID for now; are we also not setting the other headers like Host and Content-Type?

--changeset(77162fcd-b8da-41ac-a9f8-9357efbbd621)
Content-Type: application/http
Content-Transfer-Encoding:binary
Content-ID: 3
PUT /service.svc/Customers('ALFKI') HTTP/1.1
Host: host
Content-Type: application/json; odata=verbose
If-Match: xxxxx
Content-Length: ###
<Verbose JSON representation of Customer ALFKI>
--changeset(77162fcd-b8da-41ac-a9f8-9357efbbd621)--