CBQE-0: add logs

Change-Id: I7ec7282c7a43df7e82e2596aa5ff22a529570985
Reviewed-on: http://review.couchbase.org/27082
Reviewed-by: Iryna Mironava <irynamironava@yandex.ru>
Tested-by: Iryna Mironava <irynamironava@yandex.ru>