block/state: gas price for block and tx

block/block.go

@@ -107,12 +107,16 @@ type Header struct {
 	Height         uint
 	Time           time.Time
 	Fees           uint64
+	GasPrice       uint64
 	NumTxs         uint
 	LastBlockHash  []byte
 	LastBlockParts PartSetHeader
 	StateHash      []byte
 }
 
+// possible for actual gas price to be less than 1
+var GasPriceDivisor = 1000000
+
 func (h *Header) Hash() []byte {
 	buf := new(bytes.Buffer)
 	hasher, n, err := sha256.New(), new(int64), new(error)