NCBC-485: TimeSpan TTLs less than 30 days are sent as raw second TTLs.

Change-Id: Idbcca8bf03706b9adb5c3111a808d6c110ba4ab0
Reviewed-on: http://review.couchbase.org/37443
Reviewed-by: Jeffry Morris <jeffrymorris@gmail.com>
Tested-by: Jeffry Morris <jeffrymorris@gmail.com>