s390x assembler pack in CHANAGES.

Engage run-time switch between bn_mul_mont_fpu and bn_mul_mont_int.

rule to accomodate gcc4, which no longer support SGI as.

PR: 1082

[most importantly] put back dependencies accidentaly eliminated in
check-in #13342.

and GNU binutils, but kept BSD make... And I took the opportunity to
unify other targets to this common least denominator...

if $(EXHEADER) is empty.

Notified by many, solution suggested by Carson Gaspar <carson@taltos.org>

"Proper" means "compiles and passes test." Versioning is broken (I think).

COFF and a.out targets [similar to ELF targets]. You might notice some
rudementary support for shared mingw builds under cygwin. It works (it
produces cryptoeay32.dll and ssleay32.dll with everything exported by
name), but it's primarily for testing/debugging purposes, at least for
now...

I also used this opportunity to clean up some out-of-date targets and
re-group targets by OS.

especially for AIX. But most important BIGNUM assembler implementation
submitted by IBM.

Submitted by: Peter Waltenberg <pwalten@au1.ibm.com>
Reviewed by: appro

This is part of a large change submitted by Markus Friedl <markus@openbsd.org>

FreeBSD. Goal is to extend support even to SCO5, UnixWare/OpenUnix...

key-generation and prime-checking functions. Rather than explicitly passing
callback functions and caller-defined context data for the callbacks, a new
structure BN_GENCB is defined that encapsulates this; a pointer to the
structure is passed to all such functions instead.

This wrapper structure allows the encapsulation of "old" and "new" style
callbacks - "new" callbacks return a boolean result on the understanding
that returning FALSE should terminate keygen/primality processing.  The
BN_GENCB abstraction will allow future callback modifications without
needing to break binary compatibility nor change the API function
prototypes. The new API functions have been given names ending in "_ex" and
the old functions are implemented as wrappers to the new ones.  The
OPENSSL_NO_DEPRECATED symbol has been introduced so that, if defined,
declaration of the older functions will be skipped. NB: Some
openssl-internal code will stick with the older callbacks for now, so
appropriate "#undef" logic will be put in place - this is in case the user
is *building* openssl (rather than *including* its headers) with this
symbol defined.

There is another change in the new _ex functions; the key-generation
functions do not return key structures but operate on structures passed by
the caller, the return value is a boolean. This will allow for a smoother
transition to having key-generation as "virtual function" in the various
***_METHOD tables.