Destroy the engine specific pointer when clearing it on disconnect.
Destroy the engine specific pointer when clearing it on disconnect.

Change-Id: I7c0c3918cf2f6d8411da184af7f1f369f70f5f0e
Reviewed-on: http://review.northscale.com/2144
Tested-by: Steve Yen <ef850f73f7832052d3c6d9b5ddd3a1716d9a57f1@gmail.com>
Reviewed-by: Steve Yen <ef850f73f7832052d3c6d9b5ddd3a1716d9a57f1@gmail.com>

membase/bucket_engine,couchbase/bucket_engine,membase/bucket_engine,couchbase/bucket_engine,membase/bucket_engine,membase/bucket_engine,couchbase/bucket_engine,couchbase/bucket_engine