Handle abnormal exit of s_client/s_server processes.

Fixes partially #230.

Support of pkeyutl -pkeyopt ukmhex:0102030405060708 syntax

There need to be more tests than 2 constant fixed size blocks.
Final digest values are generated from the first run.

Test description in comments.

Plus some minor chnages
- function defenition doen't match function declaration
- Consecutive break statement is unnecessary.
- Type missmatch in format string

Only stack buffers are considered.

`RAND_priv_bytes' is supposed to be used for private data.

OpenSSL suggests to use (and internally itself uses)
`BN_{CTX_,}secure_new' primitives to work with private keys.

These are using `OPENSSL_secure_malloc' et al. calls, which use
special 'secure heap' memory.

Along, optimize out `hashsum2bn' with `BN_lebin2bn'.

`Test2::V0' is non standard and rarely present on systems, making `make
test' unnecessarily fail.

lcc emulates x86_64 SIMD intrinsics, so SSE2 code will work as is. Even
though in benchmarks it is slightly slower than regular implementation

This is lcc bug. Curiously, it is not triggered in `test_context.c' and
`test_grasshopper.c'.

"lcc: "/usr/src/gost-engine/test_curves.c", строка 32: ошибка:
          вероятное использование "=" вместо "=="
          [-Werror=assign-where-compare-meant]
  #define TEST_ASSERT(e) {if ((test = (e))) \
                              ^
 в раскрытие макроса "TEST_ASSERT" на строке 217
      TEST_ASSERT(0);"

"lcc: "/usr/src/gost-engine/gosthash2012_ref.h", строка 15: ошибка:
          нераспознанная #pragma [-Werror=unknown-pragmas]
  # pragma message "Use regular implementation"
           ^"

Also, cmake does not detect lcc.

There is other architectures besides __x86_64__, so EMMS should be
issued on IA-32 only where we are using MMX.

This probably would reduce size of the library. And remove
some 'not used' warnings (-Wunused-const-variable).

Previously `Ax' is generated dynamically from `A` and `Pi` in
`GOST3411Init', but in 2013 it is moved into `gosthash2012_precalc.h`.
`Tau' is unrolled and eliminated in 2013 too.

`_mm_empty' is not needed on x86_64, because we only using SSE2.

But, I didn't notice that EXTRACT32 (32-bit version of EXTRACT) is
using MMX registers and intrinsics, so complete removing of
`_mm_empty' (EMMS) was mistake.

Make it presence conditional only for IA-32.

Fixes: 211489fa ("gosthash2012: Improve SIMD implementation")

Not last version went into commit ed0f8fbe

It's not only unused, but calling _mm_extract_epi8 which is SSE4.1.

This results in ~20% improvement for reference implementation on my
Xeon E5630.

`openssl speed -evp streebog256' results (before and after):

   16 bytes    64 bytes   256 bytes  1024 bytes  8192 bytes  16384 bytes
 3815.25k   12874.41k   31497.81k   49823.06k   59932.67k    57021.78k
 4361.29k   14933.06k   37091.67k   59001.86k   71360.51k    72488.28k

Also, simple check if `_addcarry_u64' works correctly.