fix submit-block to account for fees from block reward recipient (#498)

* fix submit-block to account for fees from block reward recipient

* more thorough computation of block reward

* update miner to use function from core to recompute block reward

routes/miner.go

@@ -162,6 +162,12 @@ func (fes *APIServer) SubmitBlock(ww http.ResponseWriter, req *http.Request) {
 	blockFound.Txns[0].TxOutputs[0].PublicKey = pkBytes
 	blockFound.Txns[0].TxnMeta.(*lib.BlockRewardMetadataa).ExtraData = lib.UintToBuf(requestData.ExtraData)
 
+	blockFound, err = lib.RecomputeBlockRewardWithBlockRewardOutputPublicKey(blockFound, pkBytes)
+	if err != nil {
+		_AddBadRequestError(ww, fmt.Sprintf("SubmitBlock: Problem recomputing block reward: %v", err))
+		return
+	}
+
 	header := &lib.MsgDeSoHeader{}
 	if err := header.FromBytes(requestData.Header); err != nil {
 		_AddBadRequestError(ww, fmt.Sprintf("SubmitBlock: Problem parsing header: %v", err))