[Bro] Update on using PF_RING/TNAPI with Bro

[Sunjeet Singh]

> Why are you only running one bro process?  You can setup a single node
> bro cluster and run multiple bro processes, each listening on one of
> eth0 at 1, eth0 at 2..
>
Yes, that's a great idea. But I'm not sure how Bro would handle 
manager-proxy-worker communication between different RX_Queues instead 
of different interfaces. Can't be as simple as writing eth0 at 1, etc. in 
the cluster's node.cfg file. Maybe some changes to Bro code?

Sunjeet