ccbd09d5fb Remove unnecessary m/ prefix requirement (josibake)
Pull request description:
`m` in BIP0032 is a variable, not a constant. Requiring it as a constant here is confusing and can lead to erroneous conclusions if using this library as a means of understanding BIP0032.
Fixes#2449
ACKs for top commit:
Kixunil:
ACK ccbd09d5fb
apoelstra:
ACK ccbd09d5fb
Tree-SHA512: b641679f958f20a51c1890b23bbaa0153716802d6180dfd1f649e104f291c5a99143e02b75d292b22254201b28e5c53a04ecd7b6a88ff6f964073106419c5ec1