Adding the hooks "AddMagicWordsXX" to allow addition of localized magic words.

Adding the hooks "AddMagicWordsXX" to allow addition of localized magic words.

The current hook (LanguageGetMagic) cannot be used for internationalization,
because when we use it, we must include all the language aliases. Now we
include only the content language and English. However, this hook is retained
for backwards compatibility.