Enable a timeout to be sent to the tunnel

I have separately added support to the tunnel for receiving the timeout in the options.

I have used the same -t switch, but documented it separately in the tunnel command. Perhaps the documentation of the main -t switch should be updated to mention it's also for tunnel timeout?

I needed to extend the timeout of the tunnel for my environment and as it's an arbitrary measurement it seems like a good idea to make it an option.
Kill the tunnel when the cli process is killed

We call hangOnTillExit before the tunnel opens so that if the process is killed during the connecting phase the tunnel is still killed.
Merge pull request #2 from karlvr/tunnel-timeouts

Enable a timeout to be sent to the tunnel