changes in tunnel.py to falg the dead peers
changes in db.py to remove old peers when necessary

in upnpigd : now open a port in tcp too

in plib.py : the address attributed to the server iface was XXXXX/len(network) wich resulted in XXXXXX/48 while it should be XXXXXX/len(subnet of a single machine)
in vifibnet.py : the -l option was broken
in tunnel.py : routes count is now stored on each connection object and not in the tunnelManager object

the --ip argument is now optional : it can be discovered automaticaly

Changes in the number of connection per peers