That is, buttons and choices. Coices apparently don't work. Tried
a bit on the table heaters of the sensor and heater lists, but
found nothing which would result in an effect. This control is
not exactly well documented.
The problem was, applying tooltips to the radio buttons directly
showed no effect on Linux. While this is likely a bug in wxPython,
we can't change this behaviour.
The solution is to also apply these help texts to the surrounding
StaticBox. This works, even for the radio buttons.
This solves issue #149.