[WIP] update mac configure script and add messaging about common port forwarding issue

update mac configure script and add messaging about port forwarding until we maybe use a better solution like how libtorrent does this, or RPC & UDP like this https://github.com/bmuller/rpcudp to avoid most port forwarding issues.
however it's quite funny you say you need pip before installing virtualenv :p 

I rather leave the `easy_install pip` alone above, that was working just fine.