fixes #19988, allow html in ordinal for humanize

I've updated the humanize function to fix the i18n issue of not allowing html to do the `<sup>` for some languages.  In particular the french translation. 

Ticket: https://code.djangoproject.com/ticket/19988


```pthon
(djancon-sprint)➜  tests git:(#19988-ordinal-html-i18n-fix) ./runtests.py django.contrib.humanize
Creating test database for alias 'default'...
Creating test database for alias 'other'...
.............
----------------------------------------------------------------------
Ran 13 tests in 0.102s

OK
Destroying test database for alias 'default'...
Destroying test database for alias 'other'...
```