Networking contribution to entropy

Networking contribution to node RNG entropy

Entropy for the RNG is often harvested from network connections:

src/net.cpp

net.cpp
488-
489:    // We're making a new connection, harvest entropy from the time (and our peer count)
490-    RandAddEvent((uint32_t)id);
--
743-
744:    // We just received a message off the wire, harvest entropy from the time (and the message checksum)
745-    RandAddEvent(ReadLE32(hash.begin()));
--
1160-
1161:    // We received a new connection, harvest entropy from the time (and our peer count)
1162-    RandAddEvent((uint32_t)id);