Actuator proxying

[vs49688]

The SSH actuators should have this. Perhaps modify the config to have the following:

{
  "tunnels": [
    {
      "type": "reverse",
      "srcport": 5671,
      "dsthost": "203.101.225.94",
      "dstport": 5671
    }
  ]
}

MINA SSHD would create those tunnels upon connection. The user can specify custom AMQP/Transfer URIs in the resource configuration as normal, except this time they'd reference the head node.

[vs49688]

Needed for Nord III