NFD

TcpFactory and UdpFactory each has a "prohibited endpoint set" introduced in #1414-4 which prevents creating a face that connects to NFD itself. This was necessary at the time where forwarding strategies were dumb and there was no Nack-Duplicate.
Nowadays, this feature is no longer necessary. Although it still does not make sense to connect to NFD itself, the consequence is less severe: Interest forwarding would trigger Nack-Duplicate, and strategy is expected to handle this situation.
Therefore, "prohibited endpoint set" feature can be removed to reduce complexity of TcpFactory and UdpFactory, especially with the forthcoming dynamic face creation from fine-grained signals.