CBQE-0: add logs

Change-Id: I8cdc2dd3ba6a70ed983323ccd0e776cbc75331df
Reviewed-on: http://review.couchbase.org/27285
Reviewed-by: Iryna Mironava <irynamironava@yandex.ru>
Tested-by: Iryna Mironava <irynamironava@yandex.ru>