Use ZERO32 when needed (and fix one incorrect '0' * 32).
Use ZERO32 when needed (and fix one incorrect '0' * 32).

zsulocal/pycoin,pycoin/pycoin,shivaenigma/pycoin,mperklin/pycoin,zsulocal/pycoin,richardkiss/pycoin,mperklin/pycoin,pycoin/pycoin,richardkiss/pycoin,shivaenigma/pycoin