MB-5307: renamed vbucket_mover_start to vbucket_move_start

For consistency with vbucket_move_done. Also renamed {old,new}Chain to
chain{Before,After} for consistency with map update events.

Change-Id: I312ffa11c7bbfaeeff846b320866e2ffd2fda6ea
Reviewed-on: http://review.couchbase.org/16163
Tested-by: Aliaksey Kandratsenka <alkondratenko@gmail.com>
Reviewed-by: Aliaksey Artamonau <aliaksiej.artamonau@gmail.com>
MB-5307: disallow "after" remote master events to overtake local

I've see that some remote events that happen strictly after some local
event (i.e. stop replication on remote node versus start vbucket mover
on master) are observed before that local event, breaking causality
and making some analyzes harder.

This seemingly happens because any master event (even local) needs to
pass through it's node's "master event submitting" work queue before
getting into master events ingress queue on master node. And
apparently because master events are more frequent on master node,
some of them need more time to get to ingress queue. Allowing "after"
but "faster" remote events to overtake them.

The fix is to have ingress queue listener to double as master events
submitter. It'll check if it's node is master node and if it is it
will bypass extra queuing step (which will be to it's own queue
anyways). If it's not, it'll pass event to ingress queue on remote
master node.

So for any master event that will cause some remote event, it's now
seemingly impossible for remote event to overtake master node's event
that produced it. I.e. because master node's event is strictly prior
to remote event it will be queued before to it's ingress queue before
remote event. And thus will be fully processed before remote event.

Change-Id: I7607944b9bf47cd670aa179ad56c77d6e5e7e96d
Reviewed-on: http://review.couchbase.org/16164
Tested-by: Aliaksey Kandratsenka <alkondratenko@gmail.com>
Reviewed-by: Aliaksey Artamonau <aliaksiej.artamonau@gmail.com>
MB-5307: don't place extra quote around master events atoms

Change-Id: Icf968787b9de3bcdf42ec8981e68a000815ba278
Reviewed-on: http://review.couchbase.org/16165
Tested-by: Aliaksey Kandratsenka <alkondratenko@gmail.com>
Reviewed-by: Aliaksey Artamonau <aliaksiej.artamonau@gmail.com>
MB-5307: made ebucketmigrator terminate event dump migrator args

We now have dedicated process that keeps eye on all interesting
process and sends out configured master event when some of them dies
with vital details such as Pid and most importantly Reason.

Change-Id: I7f3c39537b6eae7a793b0a2d44626a0a573b674c
Reviewed-on: http://review.couchbase.org/16166
Tested-by: Aliaksey Kandratsenka <alkondratenko@gmail.com>
Reviewed-by: Aliaksey Artamonau <aliaksiej.artamonau@gmail.com>
MB-5307: added master activity event for death of vbucket mover

Change-Id: I249c7b34f6b6786579e3e3b7da782d6f04b45d2f
Reviewed-on: http://review.couchbase.org/16167
Tested-by: Aliaksey Kandratsenka <alkondratenko@gmail.com>
Reviewed-by: Aliaksey Artamonau <aliaksiej.artamonau@gmail.com>
MB-5307: don't stop master events streaming on unknown event

Sending empty chunk is 'end-of-response' signal. And unknown event is
formatted as empty list. Thus we need to be careful not to send empty
chunk when this happens.

Change-Id: I1abbc27d53be0aefdb8810169235d5b1f6f46899
Reviewed-on: http://review.couchbase.org/16168
Tested-by: Aliaksey Kandratsenka <alkondratenko@gmail.com>
Reviewed-by: Aliaksey Artamonau <aliaksiej.artamonau@gmail.com>
MB-5307: send out master activity event for vbucket filter change

Change-Id: Ic7f1ded2abf601d027ea11805afbc5a038cc81bc
Reviewed-on: http://review.couchbase.org/16169
Tested-by: Aliaksey Kandratsenka <alkondratenko@gmail.com>
Reviewed-by: Aliaksey Artamonau <aliaksiej.artamonau@gmail.com>
MB-5307: implemented better observing for rebalance end event

I.e. via that newer observe_fate_of facility.

Change-Id: If0ded9135c56cda631d99d39445519fc252e9996
Reviewed-on: http://review.couchbase.org/16170
Tested-by: Aliaksey Kandratsenka <alkondratenko@gmail.com>
Reviewed-by: Aliaksey Artamonau <aliaksiej.artamonau@gmail.com>