fix Tx#signature_hash_for_input for SIGHASH_SINGLE edge case

  https://bitcointalk.org/index.php?topic=260595.0

  "
    I also forked webbtc.com on mainnet today with transaction 315ac7d4c26d69668129cc352851d9389b4a6868f1509c6c8b66bead11e2619f It has two inputs, both using SIGHHASH_SINGLE, and only one output. SignatureHash() in script.cpp has the following code:

    if (nOut >= txTmp.vout.size())
    {
      printf("ERROR: SignatureHash() : nOut=%d out of range\n", nOut);
      return 1;
    }

    The thing is, that's not actually an error. SignatureHash() returns the hash of the signature, and CheckSig() doesn't check the return code, so it acts as though the hash the signature signed was 0000000000000000000000000000000000000000000000000000000000000001 You can create a signature for that, and it works just fine and the transaction is considered valid.
  "
Update litecoin seeds and checkpoints to match reference 0.8.x
pass the pubkey needed to sign along with the sig_hash
elaborate NODE documentation
fix namecoin expiration; it's 36k blocks
better error handling for #create_tx and #assemble_tx command
improve monitoring of unconfirmed tx
fix asking for getblocks
prevents blockchain sync from getting stuck (thanks warren!)
tx forwarder example demonstrating the "monitor output" and "create/assemble tx" API
automatically enable epoll and kqueue on supported systems
fix handling of services bitfield in version
fix handshaking to make sure it is fully completed for both incoming and outgoing connections
fix handshake for outgoing connections
add known_nodes for namecoin network

since we don't implement irc seed discovery, and namecoin has no dns seeds
add pure ruby version of litecoin scrypt.c

  https://github.com/litecoin-project/litecoin/blob/df06b04cf7096bce9f46fbfd81b6d79c5723be42/src/scrypt.c
make litecoin scrypt a bit more memory friendly
cleanup scrypt a bit more
add signmessage and verifymessage
reuse Bitcoin.bitcoin_signed_message_hash in  Bitcoin::Key#recover_public_key_from_signature
improve Script#get_address parsing for non-standard OP_CHECKMULTISIG