Add sighash tests from data file
Add code generating data/sighash.json test data
add checks for deserialization errors
Merge pull request #3975

81bfb5a add checks for deserialization errors (Manuel Araoz)
232aa9e Add code generating data/sighash.json test data (Manuel Araoz)
43cb418 Add sighash tests from data file (Manuel Araoz)