MB-21511 Stop dcp_replicator non-normally when socket closes.
MB-21511 Stop dcp_replicator non-normally when socket closes.

Since normal doesn't get propagated via links (in case the other
process doesn't trap exits). Specifically, it breaks the logic in
janitor_agent:wait_seqno_persisted where we link to replicator process
to ensure that we hang rebalance forever if replicator dies.

Change-Id: I311a3255607a39d29329c03747718f1a6059c275
Reviewed-on: http://review.couchbase.org/69307
Tested-by: Aliaksey Artamonau <3c875bcfb3adf2a65b2ae7686ca921e6c9433147@gmail.com>
Reviewed-by: Artem Stemkovski <15a0730a27c69f62ab86f2b6c639fca202166c02@couchbase.com>

membase/ns_server,membase/ns_server,ceejatec/ns_server,ceejatec/ns_server,membase/ns_server,membase/ns_server,ceejatec/ns_server,ceejatec/ns_server,ceejatec/ns_server,membase/ns_server,membase/ns_server,ceejatec/ns_server