MB-16452 automatically apply cert chain and pkey from inbox
MB-16452 automatically apply cert chain and pkey from inbox

...if node joins cluster with custom cluster CA. Do not allow
node to join if the chain is not signed by cluster CA

Change-Id: Ic297fd1a0901453fa3babb668db5afe1b5be987c
Reviewed-on: http://review.couchbase.org/57895
Tested-by: Artem Stemkovski <15a0730a27c69f62ab86f2b6c639fca202166c02@couchbase.com>
Reviewed-by: Aliaksey Artamonau <3c875bcfb3adf2a65b2ae7686ca921e6c9433147@gmail.com>

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