-Wmissing-prototypes -Wmissing-declarations -Wnested-externs -Winline''.

eliminate some of the -Wcast-qual warnings (debug-ben-strict target)

non-function pointers to function pointers and vice versa.
The current solution is to have unions that describe the
conversion we want to do, and gives us the ability to extract
the type of data we want.

The current solution is a quick fix, and can probably be made
in a more general or elegant way.

   CRYPTO_add_info    => CRYPTO_push_info
   CRYPTO_remove_info => CRYPTO_pop_info
in the hope that these names are more descriptive;
and "make update".

  (and that malloc can be called with an int argument).
- Use proper prototypes (with argument list) for various function pointers,
  avoid casts  (however there are still many such cases left in these files).
- Avoid collissions in app_info_cmp if sizeof int != sizeof long.
- Use CRYPTO_LOCK_MALLOC in mem_dbg.c.

 - Moved the handling of compile-time defaults from crypto.h to
   mem_dbg.c, since it doesn't make sense for the library users to try
   to affect this without recompiling libcrypto.
 - Made sure V_CRYPTO_MDEBUG_TIME and V_CRYPTO_MDEBUG_THREAD had clear
   and constant definitions.
 - Aesthetic correction.

With this change, the following is provided and present at all times
(meaning CRYPTO_MDEBUG is no longer required to get this functionality):

  - hooks to provide your own allocation and deallocation routines.
    They have to have the same interface as malloc(), realloc() and
    free().  They are registered by calling CRYPTO_set_mem_functions()
    with the function pointers.

  - hooks to provide your own memory debugging routines.  The have to
    have the same interface as as the CRYPTO_dbg_*() routines.  They
    are registered by calling CRYPTO_set_mem_debug_functions() with
    the function pointers.

I moved everything that was already built into OpenSSL and did memory
debugging to a separate file (mem_dbg.c), to make it clear what is
what.

With this, the relevance of the CRYPTO_MDEBUG has changed.  The only
thing in crypto/crypto.h that it affects is the definition of the
MemCheck_start and MemCheck_stop macros.

The info removal code was overcomplicated, and error-prone (references being wrongly decreased).  Fixed.

  1. Added code to the memory leak detecting code to give the user the
     possibility to add information, thereby forming a traceback.

  2. Make the memory leak detecting code multithread-safe.

The idea is that we're actually dealing with two separate critical
sections, one containing the hash tables with the information, the
other containing the current memory checking mode.  Those should not
be handled with the same lock, especially since their handling overlap.
Hence, the added second lock.

and make it the default for some debugging configurations.

This is much more helpful than the counter when doing tests with the library
interactively.

a pain to read when using 4-space tabs.

Submitted by:
Reviewed by:
PR: