MB-9343 close streams simultaniously on

.. consumer and producer side. this guarantees that
the subsequent add_stream will not fail with keyexist

Change-Id: I3023207596861eb0f414c7283caec2b3db0e7056
Reviewed-on: http://review.couchbase.org/33427
Tested-by: Artem Stemkovski <artem@couchbase.com>
Reviewed-by: Aliaksey Kandratsenka <alkondratenko@gmail.com>
Tested-by: Aliaksey Kandratsenka <alkondratenko@gmail.com>