SASL to LDAP translation.  plus comments and other minor changes

    ldap_domain2dn()
    ldap_domain2hostlist()
and provide prototype to soon-to-be-implemented
    ldap_dn2domain().
ldap_dnssrv_init(), if needed, can easily be implemented
using ldap_create(), ldap_set_option() and the above
commands.

Update single debug/release not to use service manager nor event manager.
Likely breaks MINGW32 port.

Add digest md5 codes to -lldap/-lldap_r (work in progress)

Add sasl.c to libldap_r.dsp.

Toy with dllimport/dllexport stuff (think I'll leave the real dll work to
somebody else).
Added ldap_strdup() wrapper of ber_strdup().

remove bogus libldap_r/apitest.ds[pw] files.

library use:
  LBER_ macros expand to system routines.
  LDAP_ macros expand to new ber_ allocators.

Add ber_ and ldap_ memory allocators/deallocator:
  ber_ routines are wrappers of LBER_ macros.
  ldap_ routines are wrappers of ber_ routines.

Removed safe_realloc() macro from various files.  This issue
(if an issue) should be resolved across whole package.

ldapmodify.c now uses ber_ allocators to resolve ber_bvfree()
vs. WIN32 multiple heaps issue.

These changes should facilate implementation of
  ber_set_option( NULL, LBER_OPT_MEMORY_FN, ...)
and
  ldap_set_option( NULL, LDAP_OPT_MEMORY_FN, ...).

This commit includes many changes.  All changes compile under NT but
have not been tested under UNIX.

A Summary of changes (likely incomplete):

NT changes:
	Removed lint.
	Clean up configuration support for "Debug", "Release", "SDebug",
		and "SRelease" configurations.
	Share output directories for clients, libraries,
		and slapd.  (maybe they should be combined further
		and moved to build/{,S}{Debug,Release}).
	Enable threading when _MT is defined.
	Enable debuging when _DEBUG is defined.
	Disable setting of NDEBUG under Release/SRelease.  Asserts
		are disabled in <ac/assert.h> when LDAP_DEBUG is not
		defined.
	Added 'build/main.dsp' Master project.
	Removed non-slapd projects from slapd.dsp (see main.dsp).
	Removed replaced many uses of _WIN32 macro with feature based
		macros.

ldap_cdefs.h changes
	#define LDAP_CONST const
		(see below)
	#define LDAP_F(type) LDAP_F_PRE type LDAP_F_POST
		To allow specifiers to be added before and after
		the type declaration.  (For DLL handling)

LBER/LDAP changes
	Namespace changes:
		s/lber_/ber_/ for here and there.
		s/NAME_ERROR/LDAP_NAME_ERROR/g
	Deleted NULLMSG and other NULL* macros for namespace reasons.
	"const" libraries.  Installed headers (ie: lber.h, ldap.h)
		use LDAP_CONST macro.  Normally set to 'const' when
		__STDC__.  Can be set externally to enable/disable
		'constification' of external interface.  Internal
		interface always uses 'const'.  Did not fix warnings
		in -lldif (in lieu of new LDIF parser).

	Added _ext API implementations (excepting search and bind).
		Need to implement ldap_int_get_controls() for reponses
		with controls.

	Added numberous assert() checks.

LDAP_R
	_MT defines HAVE_NT_THREADS
	Added numberous assert() checks.
	Changed ldap_pthread_t back to unsigned long.  Used cast
	to HANDLE in _join().

LDBM
	Replaced _WIN32 with HAVE_SYSLOG

ud
	Added version string if MKVERSION is not defined.  (MKVERSION
		needs to be set under UNIX).

slapd
	Made connection sockbuf field a pointer to a sockbuf.  This
		removed slap.h dependency on lber-int.h.  lber-int.h now only
		included by those files needing to mess with the sockbuf.
	Used ber_* functions/macros to access sockbuf internals whenever
		possible.
	Added version string if MKVERSION is not defined.  (MKVERSION
		needs to be set under UNIX).
	Removed FD_SET unsigned lint

slapd/tools
	Used EXEEXT to added ".exe" to routines.  Need to define EXEEXT
		under UNIX.

ldappasswd
	Added ldappasswd.dsp.  Ported to NT.  Used getpid() to seed rand().

nt_debug
	Minor cleanup.  Added "portable.h" include and used <ac/*.h> where
	appropriate.  Added const to char* format argument.

Removed external include/library paths from projects.  External paths should
be set via Tools | Options | Directories.  This allows each developer the
freedom to install external libraries where they desire.
Used libdb.lib instead of libdbs.lib to avoid thread conflicts.
Added hs_regex.lib to library input.  We require some form of regex, this
library works (and is relatively easy for the user to install).
Removed a little lint which MCVC5 detected.
Need to sort out single-threaded vs multithreaded library generation.

Also add initial slapd .dsw/.dsp files.  Still needs work (mainly syslog).

Fix library/include paths for building "Release".
Create getpass() from ud's mygetpass().

Added ac/stdarg.h and updated liblber encode/decode to use it.