Smarter port forwarding when using exposed_ports

[justinclayton]

Currently Pinocchio stupidly handles port forwarding via Vagrant by simply adding 1000 to each port number listed in exposed_ports. While it is at least predictable for the purpose of writing your own test steps, it is not exactly being a good citizen, as the port may already be in use on the user's host machine.

Perhaps a large port range could be used instead, with Pinocchio tracking which port was used for what and cleanly exposing that to the user so it can still be reliably referenced.

[justinclayton]

This may become much easier once Pinocchio supports Vagrant 1.1+ (which it currently does not, by the way).