``restore_ttw_functions''

Set german_token_to_words or english_token_to_words to their initial values. At the moment we only distinguish between those two, using english as a default for any other language, but other languages could be added by inserting another cond-branch equivalent to the ``german-branch''. The languages that are used should be the same as in ``sable_init_func'' and in ``set_ttw_functions''.