ENGINE surgery. DH, DSA, RAND, and RSA now use *both* "method" and ENGINE
pointers to manage their hooking with ENGINE. Previously their use of
"method" pointers was replaced by use of ENGINE references. See
crypto/engine/README for details.

Also, remove the ENGINE iterations from evp_test - even when the
cipher/digest code is committed in, this functionality would require a
different set of API calls.

ENGINE_TABLE-based stuff - as described in crypto/engine/README.

Associated miscellaneous changes;
 - the previous cipher/digest hooks that hardwired directly to EVP's
   OBJ_NAME-based storage have been backed out. New cipher/digest support
   has been constructed and will be committed shortly.
 - each implementation defines its own ENGINE_load_<name> function now.
 - the "openssl" ENGINE isn't needed or loaded any more.
 - core (not algorithm or class specific) ENGINE code has been split into
   multiple files to increase readability and decrease linker bloat.
 - ENGINE_cpy() has been removed as it wasn't really a good idea in the
   first place and now, because of registration issues, can't be
   meaningfully defined any more.
 - BN_MOD_EXP[_CRT] support is removed as per the README.
 - a bug in enginetest.c has been fixed.

NB: This commit almost certainly breaks compilation until subsequent
changes are committed.

digest support, are on their way. Rather than having gigantic commit log
messages and/or CHANGES entries, this change to the README will serve as an
outline of what it all is and how it all works.

16.

Noticed by Thomas Klausner <wiz@danbala.ifoer.tuwien.ac.at>.

recently. So comments including file names have been fixed, and copyright
notices brought up to "2001" at the same time.

and DH all conditional upon OPENSSL_NO_RSA.

tested previously.

fix a typo and add cleanup operations. This also switches on memory leak
checking (which is how the rest was found).

in "types.h" so that very few headers will need to include engine.h,
generally only C files using API functions will need it (reducing
the header dependencies quite a lot).

Fix X509V3 macro so they compile.

distinction (which does not work well because if CRYPTO_MDEBUG is
defined at library compile time, it is not necessarily defined at
application compile time; and memory debugging now can be reconfigured
at run-time anyway).  To get the intended semantics, we could just use
the EVP_DigestInit_dbg unconditionally (which uses the caller's
__FILE__ and __LINE__ for memory leak debugging), but this would make
memory debugging inconsistent.  Instead, callers can use
CRYPTO_push_info() to track down memory leaks.

distinction (which does not work well because if CRYPTO_MDEBUG is
defined at library compile time, it is not necessarily defined at
application compile time; and memory debugging now can be reconfigured
at run-time anyway).  To get the intended semantics, we could just use
the EVP_DigestInit_dbg unconditionally (which uses the caller's
__FILE__ and __LINE__ for memory leak debugging), but this would make
memory debugging inconsistent.  Instead, callers can use
CRYPTO_push_info() to track down memory leaks.

Also fix indentation, and add OpenSSL copyright.

CRYPTO_set_mem_debug_options() instead of CRYPTO_dbg_set_options(),
which is the default implementation of the former and should usually
not be directly used by applications (at least if we assume that the
options accepted by the default implementation will also be meaningful
to any other implementations).

Also fix apps/openssl.c and ssl/ssltest such that environment variable
setting 'OPENSSL_DEBUG_MEMORY=off' actively disables the compiled-in
library defaults (i.e. such that CRYPTO_MDEBUG is ignored in this
case).

<openssl/evp.h> is now used (MD_DIGEST_LENGTH definitions!).
No need to include such headers directly in md_rand.c.

(Some platforms need _XOPEN_SOURCE and _XOPEN_SOURCE_EXTENDED to get
the declaration, but on other platforms _XOPEN_SOURCE disables
the strdup declaration in <string.h>.)

In err.c, flags int_error_hash_set and int_thread_hash_set
appear superfluous since we can just as well initialize
int_error_hash and int_thread_hash to NULL.

Change some of the err.c formatting to conform with the rest of
OpenSSL.