(ripemd160_init): Use memcpy for initializing the state vector.

(COMPRESS): New macro.
(ripemd160_update): Use MD_UPDATE.
(ripemd160_digest): Inline ripemd160_final processing. Use MD_PAD
and _nettle_write_le32.
(ripemd160_final): Deleted function.

Rev: nettle/ripemd160.c:1.3