Add some spacing to faces' minimum size to avoid eliding the title
If we make the minimum size exactly the title size, we end up eliding the title even though the popup should be large enough. So add some spacing to avoid this and also to give the title a little extra room.
Completely hide the central text on pie charts when there are no total sensors
Otherwise we end up displaying the old text when removing the total sensors from config.
Don't use automatic font sizing for text on pie chart faces
Instead, use the new maximumLength function from Formatter to determine the maximum size of text and if that is too small, use the "small" font instead.