message: add comment for signature TODO
diff: @@ -182,6 +182,7 @@ impl <T: AddrLookup> State<T> {
  match self.utxos.remove(&txin.id) {
  None => {},
  Some(utxo) => {
  + // TODO verify signature
  events.push(Log::SpentFund(utxo))
  },
  }
  