support under /radios/.
The display now goes dark when the switch is turned off.
The switch position is now handled entirely within the XML -- the C++
code is generic, so that other DME receiver types can also be
modelled.
twice the design size (character height) of the old one.
Advantages:
- displays . and : correctly with less space around, and digits
with more space around (using Andy's improvements to plib)
- small text becomes much more legible (-> clock, AP-altitude)
- the font contains pretty much every character that can be
displayed on a seven segment display, so it might be more
useful for future instruments.
