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.

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

"Jan Mikkelsen" <janm@transactionsite.com> correctly states that the
OpenSSL header files have #include's and extern "C"'s in an incorrect
order.  Thusly fixed.

GeneralizedTime. At several points PKIX specifies that GeneralizedTime can be
used but OpenSSL doesn't currently support it. This patch adds several files
and a bunch of functions.

Of interest is the ASN1_TIME structure and its related functions. At several
points certificates, CRLs et al specify that a time can be expressed as a
choice of UTCTime and GeneralizedTime. Currently OpenSSL interprets this
(wrongly) as UTCTime because GeneralizedTime isn't supported. The ASN1_TIME
stuff provides this functionality.

Still todo is to trace which cert and CRL points need an ASN1_TIME and modify
the utilities appropriately and of course fix all the bugs.

Note new OpenSSL copyright in the new file a_time.c. I didn't put it in
a_gentm.c because it is a minimally modified form a_utctm.c .

Since this adds new files and error codes you will need to do a 'make errors'
at the top level to add the new codes.