#3 make usage of cyberbit as configurable option

[Stephan Walter]

For texts in roman languages (en, de, fr etc.) the
cyberbit.ttf is not required. To simplify the re-editing of
the latex source, it should be possible to deactivate the
use of the unicode ttf font.

This means that anyone with a standard latex
installation will be able to produce PDFs from the latex
source without having to go through the mess of setting
up the font files.