Add missing Slovak letters to toASCII() method

[Jimmi08]

I have Slovak text where I need to remove all accents to be able to count words.

I tried to use:

            $words_to_count = e107::getParser()->toText($words_to_count);
            $words_to_count = e107::getParser()->toASCII($words_to_count);

But it left some characters:
ľ, ú, ŕ, ô, ť

After the check, I found you are replacing only Czech characters and some of them are the same, so they were replaced correctly.
Could you add those missing ones?

Thanks.

[Jimmi08]

@CaMer0n Thank you!