Tests error reporting of transaction signing via RPC call "signrawtransaction".
Expected results:
Test 1: create and sign a valid raw transaction with one input:
- 1) The transaction has a complete set of signatures
- 2) No script verification error occurred
Test 2: create and sign a raw transaction with one valid, one invalid and one missing input script:
- 3) The transaction has no complete set of signatures
- 4) Two script verification errors occurred
- 5) Script verification errors have certain properties ("txid", "vout", "scriptSig", "sequence", "error")
- 6) The verification errors refer to the invalid (vin 1) and missing input (vin 2)
