Add new operations (set/add/replace) without ttl - see JCBC-284

Change-Id: Ia886f28e7b8b885f1100e6f949ce96ed2b228823
Reviewed-on: http://review.couchbase.org/25638
Reviewed-by: Michael Nitschinger <michael.nitschinger@couchbase.com>
Tested-by: Tugdual Grall <tugdual@gmail.com>