update commentary...

ARM assembler modules.

Also remove obsolete and now misleading comments.

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I also used this opportunity to clean up some out-of-date targets and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