Display a cyrillic buffer using a transliteration.
For readability, the table is slightly
different from the one used for the input method `cyrillic-translit'.
The argument is a string which specifies which language you are using;
that affects the choice of transliterations slightly.
Possible values are listed in `cyrillic-language-alist'.
If the argument is t, we use the default cyrillic transliteration.
If the argument is nil, we return the display table to its standard state.
(fn &optional CYRILLIC-LANGUAGE)