Add checkers for all containers

check containers services status
1) for postgres do select 1 in nailgun
2) for rabbitmq use AMQP management plugin
and fetch nodes list
3) for other containers: check listening on ports
or check processes in process list
4) add check function to dockerctl for convinience
5) add check function call to container start
Closes-Bug: #1315940
Related-Bug: #1316044

Change-Id: Id21a75718b4ad789c18aa248efca8bf16c90f6b8
Merge "Add checkers for all containers"