Support tracking blocks with multiple peers in flight
Support tracking blocks with multiple peers in flight

stevemyers/bitcoinxt,bitcoinxt/bitcoinxt,bitcoinxt/bitcoinxt,bitcoinxt/bitcoinxt,bitcoinxt/bitcoinxt,dagurval/bitcoinxt,rromanchuk/bitcoinxt,dagurval/bitcoinxt,dagurval/bitcoinxt,stevemyers/bitcoinxt,rromanchuk/bitcoinxt,dagurval/bitcoinxt,rromanchuk/bitcoinxt,stevemyers/bitcoinxt,stevemyers/bitcoinxt,stevemyers/bitcoinxt,bitcoinxt/bitcoinxt,rromanchuk/bitcoinxt,bitcoinxt/bitcoinxt,dagurval/bitcoinxt,rromanchuk/bitcoinxt,rromanchuk/bitcoinxt,dagurval/bitcoinxt,stevemyers/bitcoinxt