Add monochrome character framebuffer for monochrome
graphic dot matrix displays and electrophoretic displays.
These displays are mostly monochrome and can only display
black and some other color, for example white. Typically,
a byte controls 8 pixels, arranged vertically or horizontally
depending on the controller or settings.
The API is not suitable to display graphics, the purpose is
to display text or symbols. It is possible to use several fonts.
A font can also consist of graphic symbols only and thus,
for example, enable the realization of a menu.
Signed-off-by: Johann Fischer <j.fischer@phytec.de>
