Crypto.SM4: Add module.
Crypto: Add STREEBOG{256,512}.
Nettle.Hash: Fix AutoDoc syntax for balloon(). Also adds some related headerfile/lib paranoia.
Crypto.ECC: Add curves GOST_GC256B and GOST_GC512A.
Crypto.SHAKE_256: Add Crypto.Hash API for SHAKE_256.
Crypto.SM3: Add cipher.