With :Author:, people may think I am the only author (which is not the case,
as shown by the Git history), whereas I just wanted to specify who is the lead
developer, i.e. the person to contact. And it's not a place to list here people
that are not involved anymore in the project.

Check for dead tunnels evry 5 seconds instead of waiting for the next tunnel_refresh

in upnpigd : now open a port in tcp too

Changes in the number of connection per peers