Add an entry in CHANGES

     exchange. The LOW ciphers currently doesn't have any ciphers in it.

     [Kurt Roeckx]

  *) Make EVP_MD_CTX, EVP_MD and HMAC_CTX opaque.  For HMAC_CTX, the

     following constructors and destructors were added:

        HMAC_CTX *HMAC_CTX_new(void);

        void HMAC_CTX_free(HMAC_CTX *ctx);

     For EVP_MD, a complete API to create, fill and destroy such

     methods has been added.  See EVP_MD_meth_new(3) for

     documentation.

     Additional changes:

     1) HMAC_CTX_cleanup() and EVP_MD_CTX_cleanup() were removed,

        HMAC_CTX_init() and EVP_MD_CTX_init() should be called instead

        to reinitialise and already created structure.  Also,

        HMAC_CTX_init() and EVP_MD_CTX_init() now return 0 for failure

        and 1 for success (they previously had the return type void).

     2) For consistency with the majority of our object creators and

        destructors, EVP_MD_CTX_(create|destroy) were renamed to

        EVP_MD_CTX_(new|free).  The old names are retained as macros

        for deprecated builds.

     [Richard Levitte]

  *) Added ASYNC support. Libcrypto now includes the async sub-library to enable

     cryptographic operations to be performed asynchronously as long as an

     asynchronous capable engine is used. See the ASYNC_start_job() man page for