6e5e8d80a6 add error implementations for `ParseMagicError` and `UnknownMagic` (Noah)
a79c69894a new type network magic (Noah)
Pull request description:
#1266
Added a new type `Magic` for network magic.
ACKs for top commit:
Kixunil:
ACK 6e5e8d80a6
apoelstra:
ACK 6e5e8d80a6
Tree-SHA512: a67703e497af0e317f03d5cd4efca9ed6878c252a68aefa56592bfcac2946e8f62f1ae746de8a20344d846ec5623997acffe8a04b81b4faa25e579bebcd95f90