MB-6836 display software version on server start in user log

Change-Id: I481baed436b16b658a2a8318f2415e67d4998d1c
Reviewed-on: http://review.couchbase.org/36427
Tested-by: Artem Stemkovski <artem@couchbase.com>
Reviewed-by: Aliaksey Artamonau <aliaksiej.artamonau@gmail.com>