Allow bitcoin-tx to parse partial transactions

Restore pre V0.13.1 functionality to bitcoin-tx and allow it to parse 0-input partial transactions.

src/bitcoin-tx.cpp

@@ -629,7 +629,7 @@ static int CommandLineRawTx(int argc, char* argv[])
             if (strHexTx == "-")                 // "-" implies standard input
                 strHexTx = readStdin();
 
-            if (!DecodeHexTx(txDecodeTmp, strHexTx))
+            if (!DecodeHexTx(txDecodeTmp, strHexTx, true))
                 throw runtime_error("invalid transaction encoding");
 
             startArg = 2;

src/test/data/bitcoin-util-test.json

@@ -102,6 +102,16 @@
     "output_cmp": "txcreate2.json",
     "description": "Creates a new transaction with a single empty output script (output in json)"
   },
+  { "exec": "./bitcoin-tx",
+    "args": ["01000000000100000000000000000000000000"],
+    "output_cmp": "txcreate2.hex",
+    "description": "Parses a transation with no inputs and a single output script"
+  },
+  { "exec": "./bitcoin-tx",
+    "args": ["-json", "01000000000100000000000000000000000000"],
+    "output_cmp": "txcreate2.json",
+    "description": "Parses a transation with no inputs and a single output script (output in json)"
+  },
   { "exec": "./bitcoin-tx",
     "args":
     ["-create",