[Bitcoin-Tx] fix missing test fixtures, fix 32bit atoi issue

src/bitcoin-tx.cpp

@@ -206,7 +206,7 @@ static void MutateTxAddInput(CMutableTransaction& tx, const string& strInput)
     // extract the optional sequence number
     uint32_t nSequenceIn=std::numeric_limits<unsigned int>::max();
     if (vStrInputParts.size() > 2)
-        nSequenceIn = atoi(vStrInputParts[2]);
+        nSequenceIn = std::stoul(vStrInputParts[2]);
 
     // append to transaction input list
     CTxIn txin(txid, vout, CScript(), nSequenceIn);