Mechanism to override ts() for multi-lingual civicrm sites

It would be great if we could override the ts() function using a hook/callback.

For example, on multi-lingual sites, we have to do the following patch to CRM/Core/I18n.php:

function ts($text, $params = array())
{
// [...]
// If locale is French and if in "CiviContribute", pass strings in Drupal's t()
global $locale;
if ($locale == 'fr' && arg(1) == 'contribute')

{ $text = t($text); }

// [...]
}

This kind of hacks cannot go in core, but it would be great if we could do it using a hook.

c.f. http://forum.civicrm.org/index.php/topic,2510.msg11231.html#msg11231

Thanks,

mathieu (bgm on freenode)
http://koumbit.org