Allow initializing -> stopping state in flusher.
Allow initializing -> stopping state in flusher.

Change-Id: I29319571336a79b4fa4889eab98ae1e064b4516b
Reviewed-on: http://review.northscale.com/2131
Reviewed-by: Sean Lynch <9c3328a4a1f4f8f5c18b2d5b9057163c49b93ff3@literati.org>
Tested-by: Sean Lynch <9c3328a4a1f4f8f5c18b2d5b9057163c49b93ff3@literati.org>

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