Description:
------------
The strnatcasecmp function wrongly sorts strings in Russian, putting all uppercase letters before lowercase letters.

Test script:
---------------
<?php

echo strnatcmp("alpha", "Beta")."\t";
echo strnatcasecmp("alpha", "Beta").PHP_EOL;

echo strnatcmp("альфа", "Бета")."\t";
echo strnatcasecmp("альфа", "Бета").PHP_EOL;

?>


Expected result:
----------------
1       -1
1       -1


Actual result:
--------------
1       -1
1       1