Queue delete when deleting an expired object.
Queue delete when deleting an expired object.

Previously, a delete against an expired item would be considered
NOT_FOUND and we wouldn't see a need to queue deletion for it.  This
allows us to tell the difference and do the right thing.

Change-Id: Ia97e814902039156b7f68a92723945974f67ae28
Reviewed-on: http://review.membase.org/4242
Reviewed-by: Chiyoung Seo <8b279095f11c26cc21045fda5a3e51debb005aa9@gmail.com>
Tested-by: Chiyoung Seo <8b279095f11c26cc21045fda5a3e51debb005aa9@gmail.com>

couchbaselabs/ep-engine,jimwwalker/ep-engine,abhinavdangeti/ep-engine,abhinavdangeti/ep-engine,daverigby/ep-engine,membase/ep-engine,teligent-ru/ep-engine,zbase/ep-engine,zbase/ep-engine,sriganes/ep-engine,hisundar/ep-engine,daverigby/ep-engine,abhinavdangeti/ep-engine,daverigby/ep-engine,zbase/ep-engine,jimwwalker/ep-engine,sriganes/ep-engine,hisundar/ep-engine,membase/ep-engine,daverigby/kv_engine,owendCB/ep-engine,couchbase/ep-engine,couchbase/ep-engine,hisundar/ep-engine,jimwwalker/ep-engine,jimwwalker/ep-engine,couchbaselabs/ep-engine,sriganes/ep-engine,daverigby/kv_engine,couchbaselabs/ep-engine,zbase/ep-engine,owendCB/ep-engine,sriganes/ep-engine,owendCB/ep-engine,abhinavdangeti/ep-engine,couchbaselabs/ep-engine,couchbase/ep-engine,daverigby/ep-engine,daverigby/kv_engine,abhinavdangeti/ep-engine,owendCB/ep-engine,zbase/ep-engine,teligent-ru/ep-engine,daverigby/kv_engine,couchbaselabs/ep-engine,hisundar/ep-engine,teligent-ru/ep-engine,couchbase/ep-engine,teligent-ru/ep-engine,membase/ep-engine,membase/ep-engine