Initial import of scrypt
scrypt fixes
Replace hmac_sha256 implementation with scrypt's
We don't need sysendian.h
Indentation
hash_sha256: ref -> cp
Use cp sha256
Move crypto_hash_sha256_state to the crypto_hash_sha256.h header file
Let crypto_pwhash_scryptxsalsa208sha256 use crypto_auth_hmacsha256
Remove wrappers
Remove hashblocks*.h and sign_edwards25519sha512batch.h from sodium.h
Remove hashblocks_sha256
Remove unnecessary cast
Do not export crypto_hashblocks*
Remove useless define
Explicitly make crypto_hashblocks_sha512.h private.