Multi-byte substr

[likerRr]

Hi, great package, thx for a work.
I found an issue in format() method with 'M' format character (for short month name) for russian locale. You should consider, that russian characters are 2-bytes per symbol, so expression $translated = substr($translated, 0, 3); is incorrect. So preferred to use $translated = mb_substr($translated, 0, 3);

Maybe, it's also preferred to change any string methods to mb_ equivalent for correctly work with multibyte strings. Referenced to http://php.net/manual/en/ref.mbstring.php

Regards