Replace bitcoin by gcoin
Replace bitcoin by gcoin

1. use gcoind to start gcoin instead of bitcoind
2. use gcoin-cli to call rpc instead of bitcoin-cli

l1204366/gcoin-community,OpenNetworking/gcoin-community,OpenNetworking/gcoin-community,OpenNetworking/gcoin-community,OpenNetworking/gcoin-community,l1204366/gcoin-community,OpenNetworking/gcoin-community,l1204366/gcoin-community,l1204366/gcoin-community,OpenNetworking/gcoin-community,OpenNetworking/gcoin-community,l1204366/gcoin-community,l1204366/gcoin-community