CBQE-0: adopt tests for dp4 builds

In dp4 builds meta is stored in request content, not in header

Change-Id: Ib7442c2e33f21fbcc18ec6a0cd1a8d076231924f
Reviewed-on: http://review.couchbase.org/25846
Tested-by: buildbot <build@couchbase.com>
Reviewed-by: Andrei Baranouski <andrei.baranouski@gmail.com>