Description:
------------
mb_convert_case with MB_CASE_TITLE capitalises the 's' after an
apostrophe.

mb_convert_case with MB_CASE_TITLE capitalises the 't' after a
number.

Reproduce code:
---------------
<?php
print mb_convert_case("THE APOSTROPHE'S 'S' SHOULD NOT BE CAPITALISED",
MB_CASE_TITLE);
print mb_convert_case("IN THE 5TH CENTURY NOTING WAS CAPITALISED",
MB_CASE_TITLE);
?>


Expected result:
----------------
The Apostrophe's 'S' Should Not Be Capitalised
In The 5th Century Noting Was Capitalised

Actual result:
--------------
The Apostrophe'S 'S' Should Not Be Capitalised
In The 5Th Century Noting Was Capitalised