[Koha-translate] Javascript escape char

[Frédéric Demians]

> I think the best way is to use "'" because some other HTML
> espace sequences are already used ; like " " that can't be
> written an other way.

  being currently used doesn't mean it's the best solution.

" :" (space followed by colon) could be automatically with " :", as
simple quote could be replaced with '. And what about double quote?