CBQE-928: online upgrade with reboot

Change-Id: I6039dd35c74e99653e5c2c6bb7081d900a7e53d6
Reviewed-on: http://review.couchbase.org/24385
Reviewed-by: Iryna Mironava <irynamironava@yandex.ru>
Tested-by: Iryna Mironava <irynamironava@yandex.ru>