MB-9343 add 2 new memcached statuses ERANGE and ROLLBACK

prevent any further crashes due to unknown status

Change-Id: Ib8a51f2502d5bfe9f3639f07d3750c8a0b869bfd
Reviewed-on: http://review.couchbase.org/32831
Tested-by: Artem Stemkovski <artem@couchbase.com>
Reviewed-by: Aliaksey Artamonau <aliaksiej.artamonau@gmail.com>