Important change: Improved support for running CB "outside" of a given cloud.
With this change, the CB Orchestrator Node (ON) can contact VMs through a "jump box"
node, instead of direct establishing a network connection. In order enable it,
the following parameters have to be added to the cloud configuration file:

[VM_DEFAULTS]
CHECK_BOOT_COMPLETE = run_command_/bin/true
JUMP_HOST = "IP ADDRESS OF THE JUMP HOST"

The "check_boot_complete" parameter will instruct CB to check if the VM is fully
booted by running "/bin/true" over SSH (which goes through the "jump box"),
instead of the usual check for the openness of the port 22 (which is impossible, since
the CB's ON does not have direct network access to the VM).
The second parameter indicates the IP address of the host designated as the
actual "jump box". It is expected that this host is passwordless acessible from
the ON and that it has the binary "nc" (netcat) installed on it.
The method used to transparently access the VM through the "jump box" is the
use of the "ProxyCommand" in a custom ssh configuration file.