Updated other codes as needed.

type 'sig_atomic_t' and marked it volatile.  Add detection to
configure to ensure sig_atomic_t and volatile are supported.

if strdup fails.  This is better than not checking, but we should
add orderly shutdown.

  This could cause problems on odd systems.  The generic
  headers should be extended as needed to include necessary
  system headers or, if necessary, make explicit declarations.
Extended ac/string.h header to look for string.h/strings.h if
  STDC_HEADERS is not defined.  Also provide basic declarations for
  str*() functions.  This could cause problems on odd systems.
Extended ac/unistd.h header to define basic declaration for misc
  functions that might be missing from headers.   This includes
  externs for getenv(), getopt(), mktemp(), tempname().
Protect fax500.h from multiple inclusion.  Moved includes of
  system/generic headers back to source files.
Made mail500 helper functions static.
Fixed includes of ctype.h, signal.h, etc. to use generics.
lutil/tempname.c: was including stdlib.h twice, one should stdio.h.
Wrapped <sys/resource.h> with HAVE_SYS_RESOURCE_H.
lber/io.c/ber_get_next(): Changed noctets back to signed.
  Used with BerRead which expects signed int as second arg and
  returns signed int.

Most function and variable definitions are now preceded by its extern
definition, for error checking.  Retyped a number of functions, usually
to return void.  Fixed a number of printf format errors.

API changes (in ldap/include):
  Added avl_dup_ok, avl_prefixapply, removed ber_fatten (probably typo
  for ber_flatten), retyped ldap_sort_strcasecmp, grew lutil.h.

A number of `extern' declarations are left (some added by protoize), to
be cleaned away later.  Mostly strdup(), strcasecmp(), mktemp(), optind,
optarg, errno.

-thread & -pthread are still treated as libraries, will need
additional work to use them as CFLAGS.
Eliminated HAVE_DCE define (was redundant) and its use.  Code
now relies on draft4 and function existance tests.

in string.h was hosed for memmove/memcpy cases.

	adds POSIX RegEx (and removes BSD re_comp/re_exec) support.
* POSIX RegEx is not currently included in the distribution, however
	we will probably add Henry Spencer's REGEX library soon.
* ACL Group functionality is also included in this merge!