Speed up empty loading tons (make tests run much faster).
Speed up empty loading tons (make tests run much faster).

This takes a *tremendous* amount of time off of the test runs by
optimizing for empty data sets at load while still easing off the
processor as it learns there was more persisted data.

Change-Id: I190db64bb40a771c7a93fc49181e628ca5550e47
Reviewed-on: http://review.northscale.com/2748
Reviewed-by: Chiyoung Seo <8b279095f11c26cc21045fda5a3e51debb005aa9@gmail.com>
Tested-by: Chiyoung Seo <8b279095f11c26cc21045fda5a3e51debb005aa9@gmail.com>

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