This supplies a push notification on txid becoming known to the Hub.
Additionally this changes its close relative the AddressMonitorService
to use a different tag for the transaction data and the
double-spend-proof data so as to make it obvious which one is being
sent.
This also includes a little blockchain of 114 blocks (the first 100 just
coinbase to reach coin-maturity) with transactions generated by the
txVulcano. So lots of outputs.
I adjusted the BlackBoxTest to load this data into any hub with ease.