dict_file: change helper index_task

index_task() can now work not only with strings
dict_file.slice_list
dict_file: files
update po
translate
dict_file: fix errors
fix dict_file (missing _)
change answers of dict_file.dict_get_fake
dict_file.slice_list_to_end
dict_file: fix errors
unique chars in shortrand (fix error)
dict_file.list_len
helper for short version of quiz
model.new_quiz: make sure quiz is table
dict_file_short