Update php56 to 5.6.23 (PHP 5.6.23), including security fixes.

pkgsrc change: remove confiugre from SUBST_FILES.path.

23 Jun 2016, PHP 5.6.23

- Core:
  . Fixed bug #72275 (Integer Overflow in json_encode()/json_decode()/
    json_utf8_to_utf16()). (Stas)
  . Fixed bug #72400 (Integer Overflow in addcslashes/addslashes). (Stas)
  . Fixed bug #72403 (Integer Overflow in Length of String-typed ZVAL). (Stas)

- GD:
  . Fixed bug #72298 (pass2_no_dither out-of-bounds access). (Stas)
  . Fixed bug #72337 (invalid dimensions can lead to crash) (Pierre)
  . Fixed bug #72339 (Integer Overflow in _gd2GetHeader() resulting in
    heap overflow). (Pierre)
  . Fixed bug #72407 (NULL Pointer Dereference at _gdScaleVert). (Stas)
  . Fixed bug #72446 (Integer Overflow in gdImagePaletteToTrueColor() resulting
    in heap overflow). (Pierre)

- Intl:
  . Fixed bug #70484 (selectordinal doesn't work with named parameters).
    (Anatol)

- mbstring:
  . Fixed bug #72402 (_php_mb_regex_ereg_replace_exec - double free). (Stas)

- mcrypt:
  . Fixed bug #72455 (Heap Overflow due to integer overflows). (Stas)

- Phar:
  . Fixed bug #72321 (invalid free in phar_extract_file()).
    (hji at dyntopia dot com)

- SPL:
  . Fixed bug #72262 (int/size_t confusion in SplFileObject::fread). (Stas)
  . Fixed bug #72433 (Use After Free Vulnerability in PHP's GC algorithm and
    unserialize). (Dmitry)

- OpenSSL:
  . Fixed bug #72140 (segfault after calling ERR_free_strings()).
    (Jakub Zelenka)

- WDDX:
  . Fixed bug #72340 (Double Free Courruption in wddx_deserialize). (Stas)

- zip:
  . Fixed bug #72434 (ZipArchive class Use After Free Vulnerability in PHP's GC
    algorithm and unserialize). (Dmitry)

(taca)