Add a "fauxcyrillic" font that uses a few Cyrillic characters in place
of similarly-shaped Latin ones to create a Russian flavor in
mostly-English text.

This is reasonably close to the substitutions described at:

https://en.wikipedia.org/wiki/Faux_Cyrillic

Add a "fullcyrillic" font that replaces all of the Latin characters with
Cyrillic characters.