Add ScreenPatternList, holds all registered patterns and selects the appropriate one.
Add ScreenPatternList, holds all registered patterns and selects the appropriate one.

Signed-off-by: Raphaël Barrois <8eb3b37a023209373fcd61a2fdc08256a14fb19c@polytechnique.org>

rbarrois/mpdlcd,rbarrois/mpdlcd