start couchdb node directly without involving babysitter

...and wait for it to be fully loaded before starting ns_server_sup

this will ensure the proper loading order of processes, so the retrying
will not be needed in ns_couchdb_api

this also prevents couchdb node from being restarted when node name
changes

Change-Id: If145bbeb382b99310bcb856f0b661c143fae0b1a
Reviewed-on: http://review.couchbase.org/42582
Tested-by: Aliaksey Kandratsenka <alkondratenko@gmail.com>
Reviewed-by: Aliaksey Kandratsenka <alkondratenko@gmail.com>
start and supervise doc managers on ns_couchdb node remotely

... to enforce the proper loading and termination  order of the processes

Change-Id: I481570e964ba63eba461225521abf29099fda196
Reviewed-on: http://review.couchbase.org/42583
Tested-by: Aliaksey Kandratsenka <alkondratenko@gmail.com>
Reviewed-by: Aliaksey Kandratsenka <alkondratenko@gmail.com>