Enable flow control for intra-cluster replication by default
Enable flow control for intra-cluster replication by default

We have fixed all know issues and run a bunch of tests to ensure
that this is now working. As a result we will turn flow control
back on by default.

Change-Id: Ib3a498b9798eb7eccf03722464a220dd3f7da828
Reviewed-on: http://review.couchbase.org/38367
Reviewed-by: Sriram Ganesan <fde85c3124eed34938bb85159f430bf7e5b650f6@couchbase.com>
Tested-by: Michael Wiederhold <a17fed27eaa842282862ff7c1b9c8395a26ac320@couchbase.com>

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