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''.