extends hashlib micropython module with ripemd160 and sha512 functions.
Also adds a single-line function for pbkdf2_hmac_sha512:
pbkdf2_hmac_sha512(password, salt, iterations, bytes_to_read)
in Bitcoin to generate a seed:
pbkdf2_hmac_sha512(mnemonic, 'mnemonic'+password, 2048, 64)
- make API the same as in normal python
- make C-optimized
hmacandpbkdf2versions with standard python API