A control for rendering a cold cathode display(nixie tube).(https://en.wikipedia.org/wiki/Nixie_tube)
Can be used in DigitalDisplay
char - returns displaying char.
char=(value : Char) - sets displaying char(i.e. '0', '1', '2', '3', '4', '5', '6', '7', '8', '9', '.', ' ')
