refresh bucket info cache on node's membership changes

So that we refresh bucket info cache on niql node failover.

Change-Id: I862f2ff95eac7c481f9662f020a85e7fd9919537
Reviewed-on: http://review.couchbase.org/43152
Tested-by: Aliaksey Kandratsenka <alkondratenko@gmail.com>
Reviewed-by: Aliaksey Artamonau <aliaksiej.artamonau@gmail.com>
stop niql service on non-active nodes

Change-Id: I6eae22e8895f2a10c574f574dde1ea96f029d3aa
Reviewed-on: http://review.couchbase.org/43153
Tested-by: Aliaksey Kandratsenka <alkondratenko@gmail.com>
Reviewed-by: Aliaksey Artamonau <aliaksiej.artamonau@gmail.com>
shutdown niql service carefully by sending it shutdown message

Change-Id: I7f99a0296850b241e7939514ad43dc37f600a3b9
Reviewed-on: http://review.couchbase.org/43154
Tested-by: Aliaksey Kandratsenka <alkondratenko@gmail.com>
Reviewed-by: Aliaksey Artamonau <aliaksiej.artamonau@gmail.com>
MB-8668: unbreak saving of xdcr checkpoints

Change-Id: I679cf74c1cb2e82ed893c9a22dbad82904ce97bc
Reviewed-on: http://review.couchbase.org/43223
Tested-by: Aliaksey Kandratsenka <alkondratenko@gmail.com>
Reviewed-by: Aliaksey Artamonau <aliaksiej.artamonau@gmail.com>