seems to go a little faster but not much.
making ingest tx take a slice of txs would be faster probably.
but it seems network i/o is the limiting factor so maybe it's OK
seems to work OK. Could be sped up by local filters instead of
ingesting every tx from the block but I can do that later if
performance (mostly disk i/o) is an issue
once multiple connections are implemented, hard mode should forward
txs to blend in.
