NFD

This feature is originally proposed as a temporary solution to #2054.

As reported in #2054 note-10, NDN-RTC gets better performance with broadcast v1 than best-route v2, so I won't work on this Task recently.

I also have concern on the security of a network configured with broadcast v2: it would be much easier to launch a packet amplification attack.

After another thought, I believe permitting consumer retransmission does not increase the risk of packet amplification attack, because even without this change, consumer could set a low InterestLifetime in order to launch packet amplification attack.

This can start now, since the Nack change has been merged.

Creating a new version means incrementing the version or creating new files like multicast-strategy2.*?

I am ready to push once I get the answer to #note-9

Don't know where the NFD dev guide is/how to update it.