BigNum: numeric data fields with the number sized to fill the tile

Hi all — I've been building BigNum, and v1.1.0 is out.

It's 41 numeric data fields (speed, HR, power, cadence, climbing, time) drawn so
the number fills the field instead of sitting at the default text size in the
middle of it. That is the whole idea; the rest follows from it.

What's in it:

- Pick the typeface, and its width and weight. The default is Saira, whose
  digits are all one width, so a value stops shifting sideways as its digits
  change. Narrower digits also come out taller, because most fields run out of
  width before they run out of height.
- Optional raised decimals: 34.9 draws as 34⁹, a ride time as 1:34¹⁷. Dropping
  the point or the colon leaves the number more room.
- HR and power fields can carry their zone as colour — on the number, or filling
  the whole field — using the zones from your Karoo profile, so a field agrees
  with the rest of the device.
- Climb - Grade draws the slope as a coloured wedge behind the number, over the
  same colour bands as the Karoo's own Climber scale.

Free and open source (Apache-2.0), Karoo 2 and Karoo 3:
https://github.com/smartycoder/karoo-bignum

Feedback welcome.