MB-6844 requeue delete operation until the snapshot task is complete
MB-6844 requeue delete operation until the snapshot task is complete

This change is required to prevent any delete item on a vbucket
from persisting on the db file while the file is being created
by the snapshot. Otherwise, we could end up premature failure from
the delete opetaion.

Change-Id: I5d87bc6bdafa0381a51ae4dcb7b2885eb982e803
Reviewed-on: http://review.couchbase.org/21463
Tested-by: buildbot <80754af91bfb6d1073585b046fe0a474ce868509@couchbase.com>
Reviewed-by: Chiyoung Seo <8b279095f11c26cc21045fda5a3e51debb005aa9@gmail.com>

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