increase backlog to the highest value everywhere

It makes no sense to use -1 for *BSD (which is the highest value there)
and still use 128 for Linux.
Lets raise it right to up the limit and let the people lower it if they
think that 3.5Mb is too much for a process.
IMO this is better than silently dropping connections.
Merge branch 'PHP-5.5' of https://git.php.net/repository/php-src into PHP-5.5

* 'PHP-5.5' of https://git.php.net/repository/php-src:
  Improved performance of func_get_args() by eliminating useless copying
  Link to more readmes
  Update NEWS
  Fixed bug #65950 Field name truncation if the field name is bigger than 32 characters