Add benchmark for incrementing note witnesses

src/utiltest.h

@@ -0,0 +1,18 @@
+// Copyright (c) 2016 The Zcash developers
+// Distributed under the MIT software license, see the accompanying
+// file COPYING or http://www.opensource.org/licenses/mit-license.php.
+
+#include "wallet/wallet.h"
+#include "zcash/JoinSplit.hpp"
+#include "zcash/Note.hpp"
+#include "zcash/NoteEncryption.hpp"
+
+CWalletTx GetValidReceive(ZCJoinSplit& params,
+                          const libzcash::SpendingKey& sk, CAmount value,
+                          bool randomInputs);
+libzcash::Note GetNote(ZCJoinSplit& params,
+                       const libzcash::SpendingKey& sk,
+                       const CTransaction& tx, size_t js, size_t n);
+CWalletTx GetValidSpend(ZCJoinSplit& params,
+                        const libzcash::SpendingKey& sk,
+                        const libzcash::Note& note, CAmount value);