[PATCH v3] examples/rpcapd: demo version of packet capture daemon

[Marat Khalili]

Summarizing the exchange to v2, our own copy of rpcap-protocol.h is 
unavoidable here since one included in libpcap is an internal header 
that is not installed by design (irrespective of package maintainers). I 
am ready to ack the patch after this is clarified in the code to prevent 
other people from being similarly confused since situation with the 
dependencies here is quite complex.

My request to better mark sections of main.c responsible for different 
concerns still stands, but is not a show stopper. Same for my request to 
make it a part of dpdk-testpmd instead of a secondary process. Anyone 
interested can probably do either or both locally in half an hour in a 
code agent anyway.