BIP143: Verification logic

Includes simplifications by Eric Lombrozo.

Edited for Zcash merge by Ariel Gabizon.

src/gtest/test_checktransaction.cpp

@@ -74,7 +74,7 @@ CMutableTransaction GetValidTransaction() {
     // Empty output script.
     CScript scriptCode;
     CTransaction signTx(mtx);
-    uint256 dataToBeSigned = SignatureHash(scriptCode, signTx, NOT_AN_INPUT, SIGHASH_ALL);
+    uint256 dataToBeSigned = SignatureHash(scriptCode, signTx, NOT_AN_INPUT, SIGHASH_ALL, 0, SIGVERSION_BASE);
     if (dataToBeSigned == one) {
         throw std::runtime_error("SignatureHash failed");
     }