Finished implementing the feature for narrowing down number of server node choices.
Refactored heuristics into separate files.
Refactored and slightly adjusted LH clearing.
UNSTABLE: in the middle of major changes.  RonHeaders now support getting the sequence of addresses, RonClients can convert these into paths using m_peers and now notify heuristics about ACKs/timeouts, heuristics are being overhauled for a far more modular architecture.  More later...