Support tunneling client SSH tunnel through TLS

[anderspitman]

Sometimes the client needs to run in networks that only allow outgoing connections on ports 80/443. In this case the SSH connections for tunnels (normally port 22) will be blocked.

Now that we have the tuntls command, if we implement Server raw TLS termination and add a parameter to let the client override the tunnel SSH port, it should be possible to tunnel the tunnels through TLS.

This is rather hacky, but doesn't really require a lot of changes. Note that this will mean double encryption for every tunnel, and triple encryption for HTTPS connections over those tunnels. Definitely not ideal but I think it would work.